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Paulus S Wang - One of the best experts on this subject based on the ideXlab platform.
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Effects and Mechanisms of Nonylphenol on Corticosterone Release in Rat Zona Fasciculata-Reticularis Cells
Toxicological sciences : an official journal of the Society of Toxicology, 2010Co-Authors: Lingling Chang, Wan-song Alfred Wun, Paulus S WangAbstract:Alkylphenol ethoxylate, consisting of ∼80% nonylphenol ethoxylate (NPEO), is a major group of nonionic surfactant. The primary degradation product of NPEO, nonylphenol (NP), interferes with reproduction, induces cell death in gonads, and leads to changes in other reproductive parameters. With such apparent stress, NP is believed to induce stress response mechanism, i.e., adrenal cortical hormone. However, the effects and action mechanisms of NP on rat adrenal zona fasciculata-reticularis (ZFR) cells are still unclear. This study explored the effects of NP on Corticosterone Release. ZFR cells were incubated with NP in the presence or absence of adrenocorticotropin (ACTH), 8-bromo-cyclic 3',5'-adenosine monophosphate (8-Br-cAMP), forskolin (FSK), 25-hydroxyl cholesterol (25-OH-cholesterol), pregnenolone, progesterone, or deoxyCorticosterone at 37°C for 1 h. The concentrations of Corticosterone or pregnenolone in the spent media were measured by radioimmunoassay. The expressions of steroidogenic acute regulatory (StAR) protein, cytochrome P450 side-chain cleavage (P450scc) protein, and 11β-hydroxylase in the cells were measured by Western blot. The data demonstrated that (1) NP stimulated Corticosterone Release induced by ACTH, 8-Br-cAMP, FSK, 25-OH-cholesterol, pregnenolone, progesterone, or deoxyCorticosterone; (2) NP significantly increased pregnenolone Release in the control, 25-OH-cholesterol, trilostane, and 25-OH-cholesterol + trilostane groups; (3) NP-stimulated Corticosterone Release was estrogen receptor dependent, but mediated by nitric oxide and p38 mitogen-activated protein kinase pathway independent; and (4) NP did not affect StAR, 11β-hydroxylase, or P450scc protein expression. These results suggest that NP acts directly on rat ZFR cells to stimulate Corticosterone Release and that the stimulation mechanism of NP mediates through post-cAMP Corticosterone manufacture enzymes, i.e., P450scc and 11β-hydroxylase.
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mechanisms of inhibition of dehydroepiandrosterone upon Corticosterone Release from rat zona fasciculata reticularis cells
Journal of Cellular Biochemistry, 2008Co-Authors: Lingling Chang, Paulus S WangAbstract:We have demonstrated that dehydroepiandrosterone (DHEA) acts directly on rat zona fasciculata-reticularis (ZFR) cells to diminish Corticosterone secretion by an inhibition of post-cAMP pathway, and decreases functions of steroidogenic enzymes after P450scc as well as steroidogenic acute regulatory (StAR) protein expression. However, the mechanisms by which DHEA engages with environmental messenger signals which translate into interfering StAR protein expression are still unclear. This study explored the effects of DHEA on the phosphorylation/activation of extracellular signal-regulated kinases (ERKs). ERK activation resulted in enhancing phosphorylation of steroidogenic factor-1 (SF-1) and increased StAR protein expression. ZFR cells were incubated in the presence or absence of adrenocorticotropin (ACTH), forskolin (FSK), 25-OH-cholesterol, U0126, and H89 at 37°C. The concentration of Corticosterone Released into the media was measured by radioimmunoassay (RIA). The cells were used to extract protein for Western blot analysis of ERKs or StAR protein expression or immunoprecipitation of SF-1 analysis. The results suggested that (1) ERK pathway of rat ZFR cells might be PKA dependent, (2) ERK activity was required for SF-1 phosphorylation to upregulate steroidogenesis in rat ZFR cells, and (3) DHEA did not affect ERK phosphorylation, however, it attenuated forskolin-stimulated SF-1 phosphorylation to affect StAR protein expression. J. Cell. Biochem. 104: 359–368, 2008. © 2007 Wiley-Liss, Inc.
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Effects of crude adlay hull acetone extract on Corticosterone Release from rat zona fasciculata-reticularis cells
Naunyn-Schmiedeberg's archives of pharmacology, 2006Co-Authors: Lingling Chang, Alfred Wan Song Wun, Chien Te Hung, Shih Min Hsia, Wenchang Chiang, Paulus S WangAbstract:Adlay is a grass crop which has been used in traditional Chinese medicine and also as a nourishing food. It has been shown to posses anti-allergic, antimutagenic and hypolipemic effects. However, the effects and action mechanisms of crude adlay hull acetone extract (AHA) on adrenal zona fasciculata-reticularis (ZFR) cells are still unclear. This study explored the effects of AHA on Corticosterone Release. ZFR cells were incubated with AHA in the presence or absence of adrenocorticotropin (ACTH), 8-bromo-cyclic 3′: 5′- adenosine monophosphate (8-Br-cAMP), forskolin (FSK), 25-hydroxy cholesterol (25-OH-cholesterol), pregnenolone, progesterone or deoxyCorticosterone. The concentrations of Corticosterone or pregnenolone in the media were measured by radioimmunoassay (RIA). The cells were used to measure the expression of steroidogenic acute regulatory (StAR) protein by Western blot. The present data demonstrated that: (1) AHA inhibited ACTH-, 8-Br-cAMP-, forskolin-, 25-OH-cholesterol-, pregnenolone-, progesterone- or deoxyCorticosterone-stimulated Corticosterone Release; (2) AHA (800 μg/ml) caused more pregnenolone Release in control group, but not in 25-OH-cholesterol, trilostane or 25-OH-cholesterol+trilostane group; (3) kinetic study showed an uncompetitive inhibition model of AHA to P450 side chain cleavage enzyme (P450scc); (4) kinetic study showed a noncompetitive inhibition model of AHA to 11β-hydroxylase; and (5) AHA inhibited the expression of StAR protein. These results suggest that AHA acts directly upon rat ZFR cells to diminish Corticosterone Release. These results indicate the inhibitory mechanism of AHA mediates through an inhibition of the activities of the post-cAMP Corticosterone synthesis enzymes, i.e. 3β-HSD, 21-hydroxylase, 11β-hydroxylase, and inhibition of StAR protein expression.
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effects of dehydroepiandrosterone on Corticosterone Release in rat zona fasciculata reticularis cells
Naunyn-schmiedebergs Archives of Pharmacology, 2003Co-Authors: Lingling Chang, Lowtone L Ho, Paulus S WangAbstract:The decline of plasma dehydroepiandrosterone (DHEA) and maintenance of glucocorticoid levels with increasing age contribute to excess body fat accumulation, hyperglycaemia, hyperlipidaemia, hyperinsulinaemia and cancer. Although opposing actions of DHEA and Corticosterone have been proposed in a rat model, the effects and action mechanisms of DHEA on rat adrenal zona fasciculata-reticularis (ZFR) cells are still unclear. This study addressed the effects of DHEA on Corticosterone Release, cellular cAMP production, the functions of steroidogenic enzymes and the expression levels of steroidogenic acute regulatory protein (StAR) and cytochrome P450 side-chain cleavage enzyme (P450scc). ZFR cells were incubated with DHEA in the presence or absence of adrenocorticotropin (ACTH), 8-Br-cAMP, forskolin, 25-OH-cholesterol, pregnenolone, progesterone or deoxyCorticosterone at 37 °C for 30 min, 1 h or 5 h and the concentration of Corticosterone or pregnenolone measured subsequently in the media by RIA. The cells were used to measure the content of cAMP by RIA and to extract protein for Western blot or mRNA for RT-PCR analysis. The data demonstrated that (1) DHEA inhibited ACTH-, 8-Br-cAMP-, 25-OH-cholesterol-, pregnenolone-, progesterone- or deoxyCorticosterone-stimulated Corticosterone Release; (2) DHEA increased 25-OH-cholesterol-stimulated pregnenolone Release but not when 25-OH-cholesterol was combined with trilostane; (3) DHEA increased the K m of 11β-hydroxylase but not P450scc; (4) DHEA affected the expression levels of StAR protein but not of P450scc. These results suggest that DHEA acts directly on rat ZFR cells to diminish Corticosterone secretion by inhibition within the post-cAMP pathway, by inhibiting steroidogenic enzymes downstream from P450scc and by inhibiting StAR expression.
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Effects of S-petasin on Corticosterone Release in rats.
The Chinese journal of physiology, 2002Co-Authors: Lingling Chang, Wan-song Alfred Wun, Yi-ching Tseng, Yun-lian Lin, Paulus S WangAbstract:Petasites hybridus is used in Chinese herbal medicine. S-petasin is a bioactive compound isolated from leaves or roots of Petasites hybridus. S-petasin has been used to relieve gastrointestinal pain, lung disease, and spasms of the urogenital tract. However, the side effect of S-petasin on endocrine systems are still not clear. This study explored the effects of S-petasin on the Release of Corticosterone in vivo and in vitro. An intravenous injection of S-petasin (10 µg/kg) decreased both basal and adrenocorticotropin (ACTH)-induced plasma Corticosterone concentration in male rats. In vitro, S-petasin (3× 10 −6 -10 −4 M) caused a significant reduction of basal and ACTH-stimulated Release of Corticosterone from the enzymatically dispersed rat zona fasciculata-reticularis (ZFR) cells in a dose-dependent manner. In order to study possible mechanisms, ZFR cells were incubated with S-petasin (10 −5 M) in the presence
Lingling Chang - One of the best experts on this subject based on the ideXlab platform.
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Effects and Mechanisms of Nonylphenol on Corticosterone Release in Rat Zona Fasciculata-Reticularis Cells
Toxicological sciences : an official journal of the Society of Toxicology, 2010Co-Authors: Lingling Chang, Wan-song Alfred Wun, Paulus S WangAbstract:Alkylphenol ethoxylate, consisting of ∼80% nonylphenol ethoxylate (NPEO), is a major group of nonionic surfactant. The primary degradation product of NPEO, nonylphenol (NP), interferes with reproduction, induces cell death in gonads, and leads to changes in other reproductive parameters. With such apparent stress, NP is believed to induce stress response mechanism, i.e., adrenal cortical hormone. However, the effects and action mechanisms of NP on rat adrenal zona fasciculata-reticularis (ZFR) cells are still unclear. This study explored the effects of NP on Corticosterone Release. ZFR cells were incubated with NP in the presence or absence of adrenocorticotropin (ACTH), 8-bromo-cyclic 3',5'-adenosine monophosphate (8-Br-cAMP), forskolin (FSK), 25-hydroxyl cholesterol (25-OH-cholesterol), pregnenolone, progesterone, or deoxyCorticosterone at 37°C for 1 h. The concentrations of Corticosterone or pregnenolone in the spent media were measured by radioimmunoassay. The expressions of steroidogenic acute regulatory (StAR) protein, cytochrome P450 side-chain cleavage (P450scc) protein, and 11β-hydroxylase in the cells were measured by Western blot. The data demonstrated that (1) NP stimulated Corticosterone Release induced by ACTH, 8-Br-cAMP, FSK, 25-OH-cholesterol, pregnenolone, progesterone, or deoxyCorticosterone; (2) NP significantly increased pregnenolone Release in the control, 25-OH-cholesterol, trilostane, and 25-OH-cholesterol + trilostane groups; (3) NP-stimulated Corticosterone Release was estrogen receptor dependent, but mediated by nitric oxide and p38 mitogen-activated protein kinase pathway independent; and (4) NP did not affect StAR, 11β-hydroxylase, or P450scc protein expression. These results suggest that NP acts directly on rat ZFR cells to stimulate Corticosterone Release and that the stimulation mechanism of NP mediates through post-cAMP Corticosterone manufacture enzymes, i.e., P450scc and 11β-hydroxylase.
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mechanisms of inhibition of dehydroepiandrosterone upon Corticosterone Release from rat zona fasciculata reticularis cells
Journal of Cellular Biochemistry, 2008Co-Authors: Lingling Chang, Paulus S WangAbstract:We have demonstrated that dehydroepiandrosterone (DHEA) acts directly on rat zona fasciculata-reticularis (ZFR) cells to diminish Corticosterone secretion by an inhibition of post-cAMP pathway, and decreases functions of steroidogenic enzymes after P450scc as well as steroidogenic acute regulatory (StAR) protein expression. However, the mechanisms by which DHEA engages with environmental messenger signals which translate into interfering StAR protein expression are still unclear. This study explored the effects of DHEA on the phosphorylation/activation of extracellular signal-regulated kinases (ERKs). ERK activation resulted in enhancing phosphorylation of steroidogenic factor-1 (SF-1) and increased StAR protein expression. ZFR cells were incubated in the presence or absence of adrenocorticotropin (ACTH), forskolin (FSK), 25-OH-cholesterol, U0126, and H89 at 37°C. The concentration of Corticosterone Released into the media was measured by radioimmunoassay (RIA). The cells were used to extract protein for Western blot analysis of ERKs or StAR protein expression or immunoprecipitation of SF-1 analysis. The results suggested that (1) ERK pathway of rat ZFR cells might be PKA dependent, (2) ERK activity was required for SF-1 phosphorylation to upregulate steroidogenesis in rat ZFR cells, and (3) DHEA did not affect ERK phosphorylation, however, it attenuated forskolin-stimulated SF-1 phosphorylation to affect StAR protein expression. J. Cell. Biochem. 104: 359–368, 2008. © 2007 Wiley-Liss, Inc.
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Effects of crude adlay hull acetone extract on Corticosterone Release from rat zona fasciculata-reticularis cells
Naunyn-Schmiedeberg's archives of pharmacology, 2006Co-Authors: Lingling Chang, Alfred Wan Song Wun, Chien Te Hung, Shih Min Hsia, Wenchang Chiang, Paulus S WangAbstract:Adlay is a grass crop which has been used in traditional Chinese medicine and also as a nourishing food. It has been shown to posses anti-allergic, antimutagenic and hypolipemic effects. However, the effects and action mechanisms of crude adlay hull acetone extract (AHA) on adrenal zona fasciculata-reticularis (ZFR) cells are still unclear. This study explored the effects of AHA on Corticosterone Release. ZFR cells were incubated with AHA in the presence or absence of adrenocorticotropin (ACTH), 8-bromo-cyclic 3′: 5′- adenosine monophosphate (8-Br-cAMP), forskolin (FSK), 25-hydroxy cholesterol (25-OH-cholesterol), pregnenolone, progesterone or deoxyCorticosterone. The concentrations of Corticosterone or pregnenolone in the media were measured by radioimmunoassay (RIA). The cells were used to measure the expression of steroidogenic acute regulatory (StAR) protein by Western blot. The present data demonstrated that: (1) AHA inhibited ACTH-, 8-Br-cAMP-, forskolin-, 25-OH-cholesterol-, pregnenolone-, progesterone- or deoxyCorticosterone-stimulated Corticosterone Release; (2) AHA (800 μg/ml) caused more pregnenolone Release in control group, but not in 25-OH-cholesterol, trilostane or 25-OH-cholesterol+trilostane group; (3) kinetic study showed an uncompetitive inhibition model of AHA to P450 side chain cleavage enzyme (P450scc); (4) kinetic study showed a noncompetitive inhibition model of AHA to 11β-hydroxylase; and (5) AHA inhibited the expression of StAR protein. These results suggest that AHA acts directly upon rat ZFR cells to diminish Corticosterone Release. These results indicate the inhibitory mechanism of AHA mediates through an inhibition of the activities of the post-cAMP Corticosterone synthesis enzymes, i.e. 3β-HSD, 21-hydroxylase, 11β-hydroxylase, and inhibition of StAR protein expression.
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effects of dehydroepiandrosterone on Corticosterone Release in rat zona fasciculata reticularis cells
Naunyn-schmiedebergs Archives of Pharmacology, 2003Co-Authors: Lingling Chang, Lowtone L Ho, Paulus S WangAbstract:The decline of plasma dehydroepiandrosterone (DHEA) and maintenance of glucocorticoid levels with increasing age contribute to excess body fat accumulation, hyperglycaemia, hyperlipidaemia, hyperinsulinaemia and cancer. Although opposing actions of DHEA and Corticosterone have been proposed in a rat model, the effects and action mechanisms of DHEA on rat adrenal zona fasciculata-reticularis (ZFR) cells are still unclear. This study addressed the effects of DHEA on Corticosterone Release, cellular cAMP production, the functions of steroidogenic enzymes and the expression levels of steroidogenic acute regulatory protein (StAR) and cytochrome P450 side-chain cleavage enzyme (P450scc). ZFR cells were incubated with DHEA in the presence or absence of adrenocorticotropin (ACTH), 8-Br-cAMP, forskolin, 25-OH-cholesterol, pregnenolone, progesterone or deoxyCorticosterone at 37 °C for 30 min, 1 h or 5 h and the concentration of Corticosterone or pregnenolone measured subsequently in the media by RIA. The cells were used to measure the content of cAMP by RIA and to extract protein for Western blot or mRNA for RT-PCR analysis. The data demonstrated that (1) DHEA inhibited ACTH-, 8-Br-cAMP-, 25-OH-cholesterol-, pregnenolone-, progesterone- or deoxyCorticosterone-stimulated Corticosterone Release; (2) DHEA increased 25-OH-cholesterol-stimulated pregnenolone Release but not when 25-OH-cholesterol was combined with trilostane; (3) DHEA increased the K m of 11β-hydroxylase but not P450scc; (4) DHEA affected the expression levels of StAR protein but not of P450scc. These results suggest that DHEA acts directly on rat ZFR cells to diminish Corticosterone secretion by inhibition within the post-cAMP pathway, by inhibiting steroidogenic enzymes downstream from P450scc and by inhibiting StAR expression.
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Effects of S-petasin on Corticosterone Release in rats.
The Chinese journal of physiology, 2002Co-Authors: Lingling Chang, Wan-song Alfred Wun, Yi-ching Tseng, Yun-lian Lin, Paulus S WangAbstract:Petasites hybridus is used in Chinese herbal medicine. S-petasin is a bioactive compound isolated from leaves or roots of Petasites hybridus. S-petasin has been used to relieve gastrointestinal pain, lung disease, and spasms of the urogenital tract. However, the side effect of S-petasin on endocrine systems are still not clear. This study explored the effects of S-petasin on the Release of Corticosterone in vivo and in vitro. An intravenous injection of S-petasin (10 µg/kg) decreased both basal and adrenocorticotropin (ACTH)-induced plasma Corticosterone concentration in male rats. In vitro, S-petasin (3× 10 −6 -10 −4 M) caused a significant reduction of basal and ACTH-stimulated Release of Corticosterone from the enzymatically dispersed rat zona fasciculata-reticularis (ZFR) cells in a dose-dependent manner. In order to study possible mechanisms, ZFR cells were incubated with S-petasin (10 −5 M) in the presence
Janet A Amico - One of the best experts on this subject based on the ideXlab platform.
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Corticosterone Release in oxytocin gene deletion mice following exposure to psychogenic versus non psychogenic stress
Neuroscience Letters, 2008Co-Authors: Janet A Amico, Houming Cai, Regis R VollmerAbstract:Both anxiety-related behavior [J.A. Amico, R.C. Mantella, R.R. Vollmer, X. Li, Anxiety and stress responses in female oxytocin deficient mice, J. Neuroendocrinol. 16 (2004) 1-6; R.C. Mantella, R.R. Vollmer, X. Li, J.A. Amico, Female oxytocin-deficient mice display enhanced anxiety-related behavior, Endocrinology 144 (2003) 2291-2296] and the Release of Corticosterone following a psychogenic stress such as exposure to platform shaker was greater in female [J.A. Amico, R.C. Mantella, R.R. Vollmer, X. Li, Anxiety and stress responses in female oxytocin deficient mice, J. Neuroendocrinol. 16 (2004) 1-6; R.C. Mantella, R.R. Vollmer, L. Rinaman, X. Li, J.A. Amico, Enhanced Corticosterone concentrations and attenuated Fos expression in the medial amygdala of female oxytocin knockout mice exposed to psychogenic stress, Am. J. Physiol. Regul. Integr. Comp. Physiol. 287 (2004) R1494-R1504], but not male [R.C. Mantella, R.R. Vollmer, J.A. Amico, Corticosterone Release is heightened in food or water deprived oxytocin deficient male mice, Brain Res. 1058 (2005) 56-61], oxytocin gene deletion (OTKO) mice compared to wild type (WT) cohorts. In the present study we exposed OTKO and WT female mice to another psychogenic stress, inserting a rectal probe to record body temperature followed by brief confinement in a metabolic cage, and measured plasma Corticosterone following the stress. OTKO mice Released more Corticosterone than WT mice (P<0.03) following exposure to this stress. In contrast, if OTKO and WT female and male mice were administered insulin-induced hypoglycemia, an acute physical stress, Corticosterone Release was not different between genotypes. The absence of central OT signaling pathways in female mice heightens the neuroendocrine (e.g., Corticosterone) response to psychogenic stress, but not to the physical stress of insulin-induced hypoglycemia.
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Corticosterone Release in oxytocin gene deletion mice following exposure to psychogenic versus non-psychogenic stress.
Neuroscience letters, 2008Co-Authors: Janet A Amico, Houming Cai, Regis R VollmerAbstract:Both anxiety-related behavior [J.A. Amico, R.C. Mantella, R.R. Vollmer, X. Li, Anxiety and stress responses in female oxytocin deficient mice, J. Neuroendocrinol. 16 (2004) 1–6; R.C. Mantella, R.R. Vollmer, X. Li, J.A. Amico, Female oxytocin-deficient mice display enhanced anxiety-related behavior, Endocrinology 144 (2003) 2291–2296] and the Release of Corticosterone following a psychogenic stress such as exposure to platform shaker was greater in female [J.A. Amico, R.C. Mantella, R.R. Vollmer, X. Li, Anxiety and stress responses in female oxytocin deficient mice, J. Neuroendocrinol. 16 (2004) 1–6; R.C. Mantella, R.R. Vollmer, L. Rinaman, X. Li, J.A. Amico, Enhanced Corticosterone concentrations and attenuated Fos expression in the medial amygdala of female oxytocin knockout mice exposed to psychogenic stress, Am. J. Physiol. Regul. Integr. Comp. Physiol. 287 (2004) R1494–R1504], but not male [R.C. Mantella, R.R. Vollmer, J.A. Amico, Corticosterone Release is heightened in food or water deprived oxytocin deficient male mice, Brain Res. 1058 (2005) 56–61], oxytocin gene deletion (OTKO) mice compared to wild type (WT) cohorts. In the present study we exposed OTKO and WT female mice to another psychogenic stress, inserting a rectal probe to record body temperature followed by brief confinement in a metabolic cage, and measured plasma Corticosterone following the stress. OTKO mice Released more Corticosterone than WT mice (P
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Oxytocin knockout mice: a model for studying stress-related and ingestive behaviours
Progress in brain research, 2008Co-Authors: Janet A Amico, Houming Cai, Julie A. Miedlar, Regis R VollmerAbstract:Oxytocin (OXT) that is Released centrally is believed to be anxiolytic and have stress-attenuating effects. Oxytocin knockout (OXTKO) mice, a genetic model of OXT deficiency, have heightened Corticosterone Release after acute stress and greater anxiety-related behaviour in an elevated plus maze compared to wild-type (WT) mice. In the present set of experiments, we recorded the rise in body temperature, referred to as stress-induced hyperthermia (SIH), following transfer to a metabolic cage, which triggers both anxiety and Corticosterone Release in mice. SIH is a marker of activation of the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system. Because Corticosterone Release after acute stress is typically greater in OXTKO than in WT mice, we measured SIH as a surrogate marker of Corticosterone Release. Following transfer to a metabolic cage, both OXTKO and WT mice increased body temperature, but to the same degree. Pregnant mice, which are known to have blunted Corticosterone Release to acute stress, had attenuated SIH after transfer to a metabolic cage compared to cycling mice, but both genotypes manifested the same degree of attenuation. In addition, we tested the effects of the cannabinoid receptor 1 (CBR1) antagonist/inverse agonist (AM251) upon feeding and SIH in OXTKO versus WT mice. CBR1 antagonists are known to diminish food intake and to enhance Corticosterone both basally and following acute stress. Although AM251 blunted food intake, the effect was equivalent in both genotypes. The agent did not affect the SIH response compared to mice treated with vehicle. SIH is excellent for defining anxiolytic or blunted Corticosterone responses (such as the stress hyporesponsiveness of pregnancy), but is limited in its ability to detect the heightened Corticosterone responses that have been reported in OXTKO mice following exposure to psychogenic stress.
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Corticosterone Release is heightened in food or water deprived oxytocin deficient male mice.
Brain research, 2005Co-Authors: Rose C Mantella, Regis R Vollmer, Janet A AmicoAbstract:Recent studies in female mice that cannot synthesize oxytocin (OT) suggest that central OT neural pathways attenuate the response of the hypothalamic-pituitary-adrenal (HPA) axis to certain stressors. OT deficient (OT-/-) female mice had higher plasma Corticosterone concentrations than wild type (OT+/+) female mice following exposure to platform shaker (Mantella et al., 2004). The present study examined the Corticosterone response of OT-/- and OT+/+ male mice that were exposed to shaker stress or other stressors (i.e., administration of cholecystokinin (CCK), dehydration, or fasting) that are known to activate central OT neurons in mice. Plasma Corticosterone concentrations were higher in male mice receiving each stress than in male mice not exposed to a stressor. Plasma Corticosterone concentrations were higher in OT-/- than OT+/+ male mice that were water deprived (P < 0.05) or fasted (P < 0.03), whereas Corticosterone concentrations following exposure to platform shaker or CCK administration (10 microg/kg i.p.) were not different between genotypes. These findings support the hypothesis that absence of OT results in a heightened response of the HPA axis to certain stressors and that OT can attenuate the Corticosterone response associated with overnight food or water deprivation in male mice.
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Corticosterone Release is heightened in food or water deprived oxytocin deficient male mice.
Brain Research, 2005Co-Authors: Rose C Mantella, Regis R Vollmer, Janet A AmicoAbstract:Recent studies in female mice that cannot synthesize oxytocin (OT) suggest that central OT neural pathways attenuate the response of the hypothalamic–pituitary–adrenal (HPA) axis to certain stressors. OT deficient (OT−/−) female mice had higher plasma Corticosterone concentrations than wild type (OT+/+) female mice following exposure to platform shaker (Mantella et al., 2004). The present study examined the Corticosterone response of OT−/− and OT+/+ male mice that were exposed to shaker stress or other stressors (i.e., administration of cholecystokinin (CCK), dehydration, or fasting) that are known to activate central OT neurons in mice. Plasma Corticosterone concentrations were higher in male mice receiving each stress than in male mice not exposed to a stressor. Plasma Corticosterone concentrations were higher in OT−/− than OT+/+ male mice that were water deprived (P
Regis R Vollmer - One of the best experts on this subject based on the ideXlab platform.
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Corticosterone Release in oxytocin gene deletion mice following exposure to psychogenic versus non psychogenic stress
Neuroscience Letters, 2008Co-Authors: Janet A Amico, Houming Cai, Regis R VollmerAbstract:Both anxiety-related behavior [J.A. Amico, R.C. Mantella, R.R. Vollmer, X. Li, Anxiety and stress responses in female oxytocin deficient mice, J. Neuroendocrinol. 16 (2004) 1-6; R.C. Mantella, R.R. Vollmer, X. Li, J.A. Amico, Female oxytocin-deficient mice display enhanced anxiety-related behavior, Endocrinology 144 (2003) 2291-2296] and the Release of Corticosterone following a psychogenic stress such as exposure to platform shaker was greater in female [J.A. Amico, R.C. Mantella, R.R. Vollmer, X. Li, Anxiety and stress responses in female oxytocin deficient mice, J. Neuroendocrinol. 16 (2004) 1-6; R.C. Mantella, R.R. Vollmer, L. Rinaman, X. Li, J.A. Amico, Enhanced Corticosterone concentrations and attenuated Fos expression in the medial amygdala of female oxytocin knockout mice exposed to psychogenic stress, Am. J. Physiol. Regul. Integr. Comp. Physiol. 287 (2004) R1494-R1504], but not male [R.C. Mantella, R.R. Vollmer, J.A. Amico, Corticosterone Release is heightened in food or water deprived oxytocin deficient male mice, Brain Res. 1058 (2005) 56-61], oxytocin gene deletion (OTKO) mice compared to wild type (WT) cohorts. In the present study we exposed OTKO and WT female mice to another psychogenic stress, inserting a rectal probe to record body temperature followed by brief confinement in a metabolic cage, and measured plasma Corticosterone following the stress. OTKO mice Released more Corticosterone than WT mice (P<0.03) following exposure to this stress. In contrast, if OTKO and WT female and male mice were administered insulin-induced hypoglycemia, an acute physical stress, Corticosterone Release was not different between genotypes. The absence of central OT signaling pathways in female mice heightens the neuroendocrine (e.g., Corticosterone) response to psychogenic stress, but not to the physical stress of insulin-induced hypoglycemia.
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Corticosterone Release in oxytocin gene deletion mice following exposure to psychogenic versus non-psychogenic stress.
Neuroscience letters, 2008Co-Authors: Janet A Amico, Houming Cai, Regis R VollmerAbstract:Both anxiety-related behavior [J.A. Amico, R.C. Mantella, R.R. Vollmer, X. Li, Anxiety and stress responses in female oxytocin deficient mice, J. Neuroendocrinol. 16 (2004) 1–6; R.C. Mantella, R.R. Vollmer, X. Li, J.A. Amico, Female oxytocin-deficient mice display enhanced anxiety-related behavior, Endocrinology 144 (2003) 2291–2296] and the Release of Corticosterone following a psychogenic stress such as exposure to platform shaker was greater in female [J.A. Amico, R.C. Mantella, R.R. Vollmer, X. Li, Anxiety and stress responses in female oxytocin deficient mice, J. Neuroendocrinol. 16 (2004) 1–6; R.C. Mantella, R.R. Vollmer, L. Rinaman, X. Li, J.A. Amico, Enhanced Corticosterone concentrations and attenuated Fos expression in the medial amygdala of female oxytocin knockout mice exposed to psychogenic stress, Am. J. Physiol. Regul. Integr. Comp. Physiol. 287 (2004) R1494–R1504], but not male [R.C. Mantella, R.R. Vollmer, J.A. Amico, Corticosterone Release is heightened in food or water deprived oxytocin deficient male mice, Brain Res. 1058 (2005) 56–61], oxytocin gene deletion (OTKO) mice compared to wild type (WT) cohorts. In the present study we exposed OTKO and WT female mice to another psychogenic stress, inserting a rectal probe to record body temperature followed by brief confinement in a metabolic cage, and measured plasma Corticosterone following the stress. OTKO mice Released more Corticosterone than WT mice (P
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Oxytocin knockout mice: a model for studying stress-related and ingestive behaviours
Progress in brain research, 2008Co-Authors: Janet A Amico, Houming Cai, Julie A. Miedlar, Regis R VollmerAbstract:Oxytocin (OXT) that is Released centrally is believed to be anxiolytic and have stress-attenuating effects. Oxytocin knockout (OXTKO) mice, a genetic model of OXT deficiency, have heightened Corticosterone Release after acute stress and greater anxiety-related behaviour in an elevated plus maze compared to wild-type (WT) mice. In the present set of experiments, we recorded the rise in body temperature, referred to as stress-induced hyperthermia (SIH), following transfer to a metabolic cage, which triggers both anxiety and Corticosterone Release in mice. SIH is a marker of activation of the hypothalamic-pituitary-adrenal (HPA) axis and sympathetic nervous system. Because Corticosterone Release after acute stress is typically greater in OXTKO than in WT mice, we measured SIH as a surrogate marker of Corticosterone Release. Following transfer to a metabolic cage, both OXTKO and WT mice increased body temperature, but to the same degree. Pregnant mice, which are known to have blunted Corticosterone Release to acute stress, had attenuated SIH after transfer to a metabolic cage compared to cycling mice, but both genotypes manifested the same degree of attenuation. In addition, we tested the effects of the cannabinoid receptor 1 (CBR1) antagonist/inverse agonist (AM251) upon feeding and SIH in OXTKO versus WT mice. CBR1 antagonists are known to diminish food intake and to enhance Corticosterone both basally and following acute stress. Although AM251 blunted food intake, the effect was equivalent in both genotypes. The agent did not affect the SIH response compared to mice treated with vehicle. SIH is excellent for defining anxiolytic or blunted Corticosterone responses (such as the stress hyporesponsiveness of pregnancy), but is limited in its ability to detect the heightened Corticosterone responses that have been reported in OXTKO mice following exposure to psychogenic stress.
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Corticosterone Release is heightened in food or water deprived oxytocin deficient male mice.
Brain research, 2005Co-Authors: Rose C Mantella, Regis R Vollmer, Janet A AmicoAbstract:Recent studies in female mice that cannot synthesize oxytocin (OT) suggest that central OT neural pathways attenuate the response of the hypothalamic-pituitary-adrenal (HPA) axis to certain stressors. OT deficient (OT-/-) female mice had higher plasma Corticosterone concentrations than wild type (OT+/+) female mice following exposure to platform shaker (Mantella et al., 2004). The present study examined the Corticosterone response of OT-/- and OT+/+ male mice that were exposed to shaker stress or other stressors (i.e., administration of cholecystokinin (CCK), dehydration, or fasting) that are known to activate central OT neurons in mice. Plasma Corticosterone concentrations were higher in male mice receiving each stress than in male mice not exposed to a stressor. Plasma Corticosterone concentrations were higher in OT-/- than OT+/+ male mice that were water deprived (P < 0.05) or fasted (P < 0.03), whereas Corticosterone concentrations following exposure to platform shaker or CCK administration (10 microg/kg i.p.) were not different between genotypes. These findings support the hypothesis that absence of OT results in a heightened response of the HPA axis to certain stressors and that OT can attenuate the Corticosterone response associated with overnight food or water deprivation in male mice.
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Corticosterone Release is heightened in food or water deprived oxytocin deficient male mice.
Brain Research, 2005Co-Authors: Rose C Mantella, Regis R Vollmer, Janet A AmicoAbstract:Recent studies in female mice that cannot synthesize oxytocin (OT) suggest that central OT neural pathways attenuate the response of the hypothalamic–pituitary–adrenal (HPA) axis to certain stressors. OT deficient (OT−/−) female mice had higher plasma Corticosterone concentrations than wild type (OT+/+) female mice following exposure to platform shaker (Mantella et al., 2004). The present study examined the Corticosterone response of OT−/− and OT+/+ male mice that were exposed to shaker stress or other stressors (i.e., administration of cholecystokinin (CCK), dehydration, or fasting) that are known to activate central OT neurons in mice. Plasma Corticosterone concentrations were higher in male mice receiving each stress than in male mice not exposed to a stressor. Plasma Corticosterone concentrations were higher in OT−/− than OT+/+ male mice that were water deprived (P
Caitlin R. Gabor - One of the best experts on this subject based on the ideXlab platform.
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Stressed tadpoles mount more efficient glucocorticoid negative feedback in anthropogenic habitats due to phenotypic plasticity.
The Science of the total environment, 2020Co-Authors: Veronika Bókony, Nikolett Ujhegyi, Kamirán Á. Hamow, Jaime Bosch, Barbora Thumsová, Judit Vörös, Andrea S. Aspbury, Caitlin R. GaborAbstract:Abstract Coping with anthropogenic environmental change is among the greatest challenges faced by wildlife, and endocrine flexibility is a potentially crucial coping mechanism. Animals may adapt to anthropogenic environments by dampening their glucocorticoid stress response, but empirical tests of this hypothesis have provided mixed evidence. An alternative hypothesis is that a non-attenuated stress response and efficient negative feedback are favored in anthropogenic habitats. To test this idea, we non-invasively sampled Corticosterone Release rates of common toad (Bufo bufo) tadpoles in agricultural, urban, and natural habitats, and quantified their stress response and negative feedback by a standardized stress-and-recovery protocol. We repeated the same sampling with tadpoles raised from eggs from the same ponds in a common-garden experiment to infer if the differences observed between populations in different habitats were due to individual phenotypic plasticity rather than microevolution or transgenerational effects. We found that, compared to tadpoles in natural ponds, urban tadpoles had higher baseline and stressed Corticosterone Release rates, and tadpoles in agricultural ponds had similar Corticosterone Release rates but greater stress-induced change, indicating stronger stress responses in both types of anthropogenic habitats. As predicted, tadpoles in both agricultural and urban ponds showed more efficient negative feedback than did tadpoles in natural ponds. Water pollution levels, as indicated by the concentrations of carbamazepine and corticoid-disrupting compounds in pond water, contributed to elevating the stress response regardless of land use. Infection by neither Batrachochytrium dendrobatidis nor Ranavirus was detected in free-living tadpoles. No habitat-related glucocorticoid differences persisted in the common-garden experiment. These results suggest that toad tadpoles in anthropogenic habitats increased their glucocorticoid flexibility via phenotypic plasticity. The coupling of stronger stress response and stronger negative feedback in these habitats supports the importance of rapidly “turning on and off” the stress response as a mechanism for coping with anthropogenic environmental change.
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Validation of water-borne cortisol and Corticosterone in tadpoles: Recovery rate from an acute stressor, repeatability, and evaluating rearing methods.
General and comparative endocrinology, 2019Co-Authors: Zachery R. Forsburg, Cory B. Goff, Hannah R. Perkins, Joseph A. Robicheaux, Grayson F. Almond, Caitlin R. GaborAbstract:Abstract Amphibian populations are declining globally, so understanding how individuals respond to anthropogenic and environmental stressors may aid conservation efforts. Using a non-invasive water-borne hormone assay, we measured the Release rates of two glucocorticoid hormones, Corticosterone and cortisol, in Rio Grande Leopard frog, Rana berlandieri , tadpoles. We validated this method pharmacologically and biologically using an adrenocorticotropic hormone (ACTH) challenge, exposure to exogenous Corticosterone, and an agitation test. We calculated the repeatability of hormone Release rates, the recovery time from an acute stressor, and explored rearing methods for tadpoles. Tadpole Corticosterone Release rates increased following an ACTH challenge, exposure to exogenous Corticosterone, and agitation, validating the use of water-borne hormone methods in this species. After exposure to an acute stressor via agitation, Corticosterone Release rates began to decline after 2 h and were lowest after 6 h, suggesting a relatively rapid recovery from an acute stressor. Tadpoles reared in groups had higher Corticosterone Release rates than tadpoles reared individually, and lost mass by Day 7, while tadpoles reared individually did not show a stress response, therefore either rearing method is viable, but have differing physiological costs for tadpoles. Repeatability of Corticosterone Release rates was moderate to high in R. berlandieri tadpoles, indicating that this species can show a response to selection and potentially respond to rapid environmental change. Our results show that the water-borne hormone assay is a viable way to measure glucocorticoids in this species and is useful in the field of conservation physiology for rare and endangered species.
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Cross-Life Stage Effects of Aquatic Larval Density and Terrestrial Moisture on Growth and Corticosterone in the Spotted Salamander
Diversity, 2018Co-Authors: Julie F. Charbonnier, Jacquelyn Pearlmutter, James R. Vonesh, Caitlin R. Gabor, Zachery R. Forsburg, Kristine L. GraysonAbstract:For organisms with complex life cycles, conditions experienced during early life stages may constrain later growth and survival. Conversely, compensatory mechanisms may attenuate negative effects from early life stages. We used the spotted salamander, Ambystoma maculatum, to test how aquatic larval density and terrestrial moisture influence juvenile growth, food intake, evaporative water loss and water reuptake rates, and Corticosterone levels. We conducted an outdoor mesocosm experiment to manipulate larval density and transferred metamorphosed salamanders into low and high terrestrial moisture treatments in laboratory terrariums. After the larval stage, high-density salamanders were significantly smaller and had higher Corticosterone Release rates than those from low-density treatments. Salamanders in the low terrestrial moisture treatment consumed fewer roaches, had lower mass-specific growth rates, higher water reuptake, and higher Corticosterone Release rates than salamanders in high terrestrial moisture treatments. Across moisture treatments, smaller salamanders had higher mass-specific growth rates than larger salamanders. Our results suggest that salamanders can partially compensate for competition in the larval aquatic habitat with increased growth as juveniles, but this response is dependent on terrestrial habitat quality. Thus, the persistence of early life stage effects can be an important, yet context-dependent, component of amphibian life cycles.
