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Liya Qiao - One of the best experts on this subject based on the ideXlab platform.

  • involvement of a putative g protein coupled receptor and a branching pathway in Argipressin 4 8 signal transduction in rat hippocampus
    Acta Pharmacologica Sinica, 1998
    Co-Authors: Liya Qiao
    Abstract:

    AIM: To study the signal transduction pathway induced by Argipressin (4-8) (AVP4-8) in rat hippocampus. METHODS: Rat hippocampi were sectioned transversely at 300 microns with a tissue chopper and transferred to fresh incubation solution circulated with a humidified gas mixture of 95% O2 + 5% CO2 at 36 +/- 0.5 degrees C. After incubation with various drugs, MAP kinase (MAPK) activity and Ca2+/calmodulin-dependent protein kinase II (CaMKII) autophosphorylation were measured. RESULTS: The main findings are: (1) The AVP4-8-stimulated MAPK activity and the CaMKII autophosphorylation were blocked by ZDC(C)PR, an antagonist of AVP4-8, and also completely inhibited by pertussis toxin, a selective inhibitor of the G-protein-coupled receptor (GPCR). But, AVP-induced MAPK activation was not sensitive to ZDC(C)PR or PTX. (2) Polymyxin B (PMB), an inhibitor of protein kinase C (PKC), markedly suppressed the peptide-activation of MAPK, but did not affect CaMKII autophosphorylation. Phorbol myristate acetate (TPA), an activator of PKC, elicited an increase of MAPK activity, but did not further influence the level of AVP4-8-enhanced MAPK activity; Nevertheless, the extent of CaMKII activation was attenuated by TPA. (3) The enhancement of MAPK activity was not reduced by KN-62, a specific inhibitor of CaMKII. (4) AVP4-8 did not show any influence on cAMP production. CONCLUSION: AVP4-8 stimulated signal transduction via a GPCR and a branching pathway in rat hippocampus.

  • increase of mitogen activated protein kinase activity in rat brain after injection of Argipressin 4 8
    Acta Pharmacologica Sinica, 1997
    Co-Authors: Liya Qiao
    Abstract:

    AIM: To study the changes of mitogen-activated protein kinase (MAPK) activity in rat brain stimulated by Argipressin (4-8) (AVP (4-8)) (s.c.). METHODS: Wistar rat was treated with AVP (4-8). MAPK activity in rat brain was assayed by phosphorylation of its specific substrate myelin basic protein (MBP) after the cytosolic extracts fractionated by MONO-Q anion-exchange chromatography. RESULTS: The activity of 44 kDa MAPK in rat brain was significantly enhanced by AVP (4-8). The enhancement of MAPK activity in hippocampus was suppressed 80% by ZDC(C)CPR, an antagonist of AVP(4-8). The level of 44 kDa MAPK protein had no detectable differences between the administration groups and control. In rat hippocampal slices, similar results were obtained. CONCLUSION: The increasement of 44 kDa MAPK activity stimulated by AVP(4-8) was mediated by its specific receptor, and was a short-period process activated by protein phosphorylation, but not by protein expression. MAPK was involved in the signal transduction pathway induced by AVP(4-8).

Ying Xiong - One of the best experts on this subject based on the ideXlab platform.

  • Argipressin 4 8 upregulate ctp phosphocholine cytidylyltransferase in rat hippocampal neurons
    Acta Biochimica et Biophysica Sinica, 2002
    Co-Authors: Ying Xiong
    Abstract:

    In order to study the effect of Argipressin(4-8) (AVP(4-8)) on the mRNA level and activity of cytidine triphosphate: phosphocholine cytidylyltransferase (CCT) in rat hippocampal neurons, and elucidate its possible mechanism. Rat hippocampal neurons treated with AVP(4-8) or actinomycin D were incubated with different time periods. The mRNA level of CCT was detected using RT-PCR plus Southern blot, CCT activity was determined by measuring the rate of incorporation of [C-14]- phosphocholine into cytidine diphosphate-choline (CDP-choline). It was found that AVP(4-8) could upregulate the CCT mRNA in rat hippocampal neurons. ZDC(C)PR, the antagonist of AVP(4-8), could greatly inhibit this upregulation. Using actinomycin D to inhibite the eucaryotic transcription, it was found that the halflife of CCT mRNA could be prolonged by coincubation with AVP(4-8). Meanwhile, AVP(4-8) could also increase CCT activity in rat hippocampal neurons. These results demonstrated that AVP(4-8) upregulated CCT mRNA level and its activity through stabilizing the CCT mRNA in rat hippocampal neurons.

  • memory enhancing effects of Argipressin and its relationship with periaqueductal gray
    Acta Pharmacologica Sinica, 1994
    Co-Authors: Ying Xiong, Changcheng Zhang, Guanghui Zhang
    Abstract:

    Wistar rats were trained to perform shuttle-box active avoidance response. In experiment A, 43 rats were implanted cannulae in bilateral periaqueductal gray (PAG) and Argipressin (Arg) was injected. Arg 0.15 or 0.3 ng but not 0.05 ng retarded the extinction of avoidance response. In experiment B, 37 rats were set up bilateral electrolytic lesions of PAG or sham lesioned. Arg (6 micrograms.kg-1, ip) was injected after training. PAG lesions blocked the influence of ip Arg on memory enhancement. The results indicated that Arg may act directly on CNS to modulated memory and PAG may play an important role in this process. This observation provided further support to the previous suggestion that certain limbic midbrain structures were involved in memory-enhancement by Arg.

Zhibing Liu - One of the best experts on this subject based on the ideXlab platform.

  • effect of Argipressin and its related compounds on corticotropin releasing hormone contents in hypothalamus of rats
    Acta Pharmacologica Sinica, 1991
    Co-Authors: Zhibing Liu
    Abstract:

    The paper mainly stresses on the effect of Argipressin (Arg), 2-destyrosyl-3-desphenyl-alanyl-9-desglycyl-amide-Arg (Arg4-8), [1-deaminopenicillamine, 2-(o-methyl)tyrosine]-Arg (DPArg) and Arg antiserum on corticotropin releasing hormone (CRH) contents in median eminence (ME) and the level of plasma corticosterone after injected into the third ventricle of rats. The results show: 1) the CRH contents in ME significantly reduced with icv 100, 200, and 800 ng of Arg; 2) 100 ng of Arg4-8 and Arg antiserum (2 microliters, 1:1 diluted with 0.9% saline) increased CRH contents in ME and enhanced plasma corticosterone; 3) DPArg had no effect on CRH level but blocked the inhibitory role of Arg on central CRH. These results suggest that Arg acts as an inhibitory factor in regulating central CRH level and V1 receptor is involved.

Nai Chang Jiang - One of the best experts on this subject based on the ideXlab platform.

  • Cardiovascular effects of injection of Argipressin into lateral septal nuclei in rats
    Zhongguo yao li xue bao = Acta pharmacologica Sinica, 1996
    Co-Authors: Lie Gao, Nai Chang Jiang, Qing Hua Luo, Zhu Xia Zhu
    Abstract:

    "AIM: To determine whether Argipressin (Arg) plays a role in central neural control of cardiovascular function by acting on the lateral septal nuclei (LSN). METHODS: Measuring mean arterial blood pressure (MAP) and heart rate (HR) responses followed microinjection of Arg into the LSN of rats anesthetized with urethane. RESULTS: Arg (100, 200, and 400 ng) injected into the LSN produced a dose-dependent hypertension and tachycardia. Maximal changes of MAP were 0.9 +/- 0.6, 2.3 +/- 1.3, 4.0 +/- 1.4 kPa, respectively; maximal changes of HR were 12 +/- 27, 50 +/- 33, and 89 +/- 27 bpm, respectively. Pretreatment of the LSN with a vasopressin 1 type antagonist d (CH2)5Tyr(Me) Arg abolished the MAP and HR responses produced by injection of Arg. Peripheral alpha-adrenergic blockade with phentolamine blocked the hypertension responses to injection of Arg into the LSN. CONCLUSION: Arg acts in the region of the LSN to exert a central action on the cardiovascular system that is mediates by stimulation of sympathetic outflow. "

  • effects of Argipressin injected into medial amygdaloid body on blood pressure and heart rate in rats
    Acta Pharmacologica Sinica, 1993
    Co-Authors: Nai Chang Jiang, Lie Gao, Chan Chen, Ya Pan, Dicheng Liu
    Abstract:

    Graded injections of Argipressin (Arg, 150, 300, and 600 ng/1.5 microliters CSF, 2 min) into the medial amygdaloid body in anesthetized rats produced a dose-related increase in the mean arterial pressure and heart rate (Maximal delta MAP = 2.9 +/- 1.5 kPa, Maximal delta HR = 67 +/- 38 bpm), which lasting > 40 min at 600 ng dosage. Naloxone (15 micrograms/15 microliters CSF) injected into the lateral ventricle blocked the cardiovascular responses to Arg. These results suggest that Arg exerts a central action on the cardiovascular system via the opioid in the lateral ventricle.

Lie Gao - One of the best experts on this subject based on the ideXlab platform.

  • Cardiovascular effects of injection of Argipressin into lateral septal nuclei in rats
    Zhongguo yao li xue bao = Acta pharmacologica Sinica, 1996
    Co-Authors: Lie Gao, Nai Chang Jiang, Qing Hua Luo, Zhu Xia Zhu
    Abstract:

    "AIM: To determine whether Argipressin (Arg) plays a role in central neural control of cardiovascular function by acting on the lateral septal nuclei (LSN). METHODS: Measuring mean arterial blood pressure (MAP) and heart rate (HR) responses followed microinjection of Arg into the LSN of rats anesthetized with urethane. RESULTS: Arg (100, 200, and 400 ng) injected into the LSN produced a dose-dependent hypertension and tachycardia. Maximal changes of MAP were 0.9 +/- 0.6, 2.3 +/- 1.3, 4.0 +/- 1.4 kPa, respectively; maximal changes of HR were 12 +/- 27, 50 +/- 33, and 89 +/- 27 bpm, respectively. Pretreatment of the LSN with a vasopressin 1 type antagonist d (CH2)5Tyr(Me) Arg abolished the MAP and HR responses produced by injection of Arg. Peripheral alpha-adrenergic blockade with phentolamine blocked the hypertension responses to injection of Arg into the LSN. CONCLUSION: Arg acts in the region of the LSN to exert a central action on the cardiovascular system that is mediates by stimulation of sympathetic outflow. "

  • effects of Argipressin injected into medial amygdaloid body on blood pressure and heart rate in rats
    Acta Pharmacologica Sinica, 1993
    Co-Authors: Nai Chang Jiang, Lie Gao, Chan Chen, Ya Pan, Dicheng Liu
    Abstract:

    Graded injections of Argipressin (Arg, 150, 300, and 600 ng/1.5 microliters CSF, 2 min) into the medial amygdaloid body in anesthetized rats produced a dose-related increase in the mean arterial pressure and heart rate (Maximal delta MAP = 2.9 +/- 1.5 kPa, Maximal delta HR = 67 +/- 38 bpm), which lasting > 40 min at 600 ng dosage. Naloxone (15 micrograms/15 microliters CSF) injected into the lateral ventricle blocked the cardiovascular responses to Arg. These results suggest that Arg exerts a central action on the cardiovascular system via the opioid in the lateral ventricle.