The Experts below are selected from a list of 10068 Experts worldwide ranked by ideXlab platform
Laurival A De Luca - One of the best experts on this subject based on the ideXlab platform.
-
Water Deprivation partial rehydration induces sensitization of sodium appetite and alteration of hypothalamic transcripts
American Journal of Physiology-regulatory Integrative and Comparative Physiology, 2016Co-Authors: Daniela T B Pereiraderderian, Regina Célia Vendramini, Jose Vanderlei Menani, Silvana Chiavegatto, Laurival A De LucaAbstract:iSodium intake occurs either as a spontaneous or induced behavior, which is enhanced, i.e., sensitized, by repeated episodes of Water Deprivation followed by subsequent partial rehydration (WD-PR). In the present work, we examined whether repeated WD-PR alters hypothalamic transcripts related to the brain renin-angiotensin system (RAS) and apelin system in male normotensive Holtzman rats (HTZ). We also examined whether the sodium intake of a strain with genetically inherited high expression of the brain RAS, the spontaneously hypertensive rat (SHR), responds differently than HTZ to repeated WD-PR. We found that repeated WD-PR, besides enhancing spontaneous and induced 0.3 M NaCl intake, increased the hypothalamic expression of angiotensinogen, aminopeptidase N, and apelin receptor transcripts (43%, 60%, and 159%, respectively) in HTZ at the end of the third WD-PR. Repeated WD-PR did not change the daily spontaneous 0.3 M NaCl intake and barely changed the need-induced 0.3 M NaCl intake of SHR. The same treatment consistently enhanced spontaneous daily 0.3 M NaCl intake in the normotensive Wistar-Kyoto rats. The results show that repeated WD-PR produces alterations in hypothalamic transcripts and also sensitizes sodium appetite in HTZ. They suggest an association between the components of hypothalamic RAS and the apelin system, with neural and behavioral plasticity produced by repeated episodes of WD-PR in a normotensive strain. The results also indicate that the inherited hyperactive brain RAS is not a guarantee for sensitization of sodium intake in the male adult SHR exposed to repeated WD-PR.
-
mapping brain fos immunoreactivity in response to Water Deprivation and partial rehydration influence of sodium intake
Physiology & Behavior, 2015Co-Authors: Carolina Dalmasso, Jose Antunesrodrigues, Laura Vivas, Laurival A De LucaAbstract:Water Deprivation (WD) followed by Water intake to satiety, produces satiation of thirst and partial rehydration (PR). Thus, WD-PR is a natural method to differentiate thirst from sodium appetite. WD-PR also produces Fos immunoreactivity (Fos-ir) in interconnected areas of a brain circuit postulated to subserve sodium appetite. In the present work, we evaluated the effect of sodium intake on Fos-ir produced by WD-PR in brain areas operationally defined according to the literature as either facilitatory or inhibitory to sodium intake. Isotonic NaCl was available for ingestion in a sodium appetite test performed immediately after a single episode of WD-PR. Sodium intake decreased Fos-ir in facilitatory areas such as the lamina terminalis (particularly subfornical organ and median preoptic nucleus), central amygdala and hypothalamic parvocellular paraventricular nucleus in the forebrain. Sodium intake also decreased Fos-ir in inhibitory areas such as the area postrema, lateral parabrachial nucleus and nucleus of the solitary tract in the hindbrain. In contrast, sodium intake further increased Fos-ir that was activated by Water Deprivation in the dorsal raphe nucleus, another inhibitory area localized in the hindbrain. WD-PR increased Fos-ir in the core and shell of the nucleus accumbens. Sodium intake reduced Fos-ir in both parts of the accumbens. In summary, sodium intake following WD-PR reduced Fos-ir in most facilitatory and inhibitory areas, but increased Fos-ir in another inhibitory area. It also reduced Fos-ir in a reward area (accumbens). The results suggest a functional link between sodium intake and the activity of the hindbrain-forebrain circuitry subserving reward and sodium appetite in response to Water Deprivation.
-
Water Deprivation induced sodium appetite humoral and cardiovascular mediators and immediate early genes
American Journal of Physiology-regulatory Integrative and Comparative Physiology, 2002Co-Authors: Laurival A De Luca, Jose Vanderlei Menani, Guus H M Schoorlemmer, Robert L Thunhorst, Terry G Beltz, Alan Kim JohnsonAbstract:Adult rats deprived of Water for 24-30 h were allowed to rehydrate by ingesting only Water for 1-2 h. Rats were then given access to both Water and 1.8% NaCl. This procedure induced a sodium appetite defined by the operational criteria of a significant increase in 1.8% NaCl intake (3.8 +/- 0.8 ml/2 h; n = 6). Expression of Fos (as assessed by immunohistochemistry) was increased in the organum vasculosum of the lamina terminalis (OVLT), median preoptic nucleus (MnPO), subfornical organ (SFO), and supraoptic nucleus (SON) after Water Deprivation. After rehydration with Water but before consumption of 1.8% NaCl, Fos expression in the SON disappeared and was partially reduced in the OVLT and MnPO. However, Fos expression did not change in the SFO. Water Deprivation also 1) increased plasma renin activity (PRA), osmolality, and plasma Na+; 2) decreased blood volume; and 3) reduced total body Na+; but 4) did not alter arterial blood pressure. Rehydration with Water alone caused only plasma osmolality and plasma Na+ concentration to revert to euhydrated levels. The changes in Fos expression and PRA are consistent with a proposed role for ANG II in the control of the sodium appetite produced by Water Deprivation followed by rehydration with only Water.
De-hua Wang - One of the best experts on this subject based on the ideXlab platform.
-
Water Deprivation up-regulates urine osmolality and renal aquaporin 2 in Mongolian gerbils (Meriones unguiculatus).
Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 2016Co-Authors: De-hua WangAbstract:To better understand how desert rodents adapt to Water scarcity, we examined urine osmolality, renal distribution and expression of aquaporins (AQPs) in Mongolian gerbils (Meriones unguiculatus) during 7 days of Water Deprivation (WD). Urine osmolality of the gerbils during WD averaged 7503 mOsm kg(-1). Renal distributions of AQP1, AQP2, and AQP3 were similar to that described in other rodents. After the 7 day WD, renal AQP2 was up-regulated, while resting metabolic rate and total evaporative Water loss decreased by 43% and 36%, respectively. Our data demonstrated that Mongolian gerbils showed high urine concentration, renal AQPs expression and body Water conservation to cope with limited Water availability, which may be critical for their survival during dry seasons in cold deserts.
-
Water Deprivation up regulates urine osmolality and renal aquaporin 2 in mongolian gerbils meriones unguiculatus part a molecular integrative physiology
Comparative Biochemistry and Physiology, 2016Co-Authors: De-hua WangAbstract:To better understand how desert rodents adapt to Water scarcity, we examined urine osmolality, renal distribution and expression of aquaporins (AQPs) in Mongolian gerbils (Meriones unguiculatus) during 7days of Water Deprivation (WD). Urine osmolality of the gerbils during WD averaged 7503mOsmkg⁻¹. Renal distributions of AQP1, AQP2, and AQP3 were similar to that described in other rodents. After the 7day WD, renal AQP2 was up-regulated, while resting metabolic rate and total evaporative Water loss decreased by 43% and 36%, respectively. Our data demonstrated that Mongolian gerbils showed high urine concentration, renal AQPs expression and body Water conservation to cope with limited Water availability, which may be critical for their survival during dry seasons in cold deserts.
Regina Célia Vendramini - One of the best experts on this subject based on the ideXlab platform.
-
Water Deprivation partial rehydration induces sensitization of sodium appetite and alteration of hypothalamic transcripts
American Journal of Physiology-regulatory Integrative and Comparative Physiology, 2016Co-Authors: Daniela T B Pereiraderderian, Regina Célia Vendramini, Jose Vanderlei Menani, Silvana Chiavegatto, Laurival A De LucaAbstract:iSodium intake occurs either as a spontaneous or induced behavior, which is enhanced, i.e., sensitized, by repeated episodes of Water Deprivation followed by subsequent partial rehydration (WD-PR). In the present work, we examined whether repeated WD-PR alters hypothalamic transcripts related to the brain renin-angiotensin system (RAS) and apelin system in male normotensive Holtzman rats (HTZ). We also examined whether the sodium intake of a strain with genetically inherited high expression of the brain RAS, the spontaneously hypertensive rat (SHR), responds differently than HTZ to repeated WD-PR. We found that repeated WD-PR, besides enhancing spontaneous and induced 0.3 M NaCl intake, increased the hypothalamic expression of angiotensinogen, aminopeptidase N, and apelin receptor transcripts (43%, 60%, and 159%, respectively) in HTZ at the end of the third WD-PR. Repeated WD-PR did not change the daily spontaneous 0.3 M NaCl intake and barely changed the need-induced 0.3 M NaCl intake of SHR. The same treatment consistently enhanced spontaneous daily 0.3 M NaCl intake in the normotensive Wistar-Kyoto rats. The results show that repeated WD-PR produces alterations in hypothalamic transcripts and also sensitizes sodium appetite in HTZ. They suggest an association between the components of hypothalamic RAS and the apelin system, with neural and behavioral plasticity produced by repeated episodes of WD-PR in a normotensive strain. The results also indicate that the inherited hyperactive brain RAS is not a guarantee for sensitization of sodium intake in the male adult SHR exposed to repeated WD-PR.
-
Water Deprivation induced sodium appetite and differential expression of encephalic c fos immunoreactivity in the spontaneously hypertensive rat
American Journal of Physiology-regulatory Integrative and Comparative Physiology, 2010Co-Authors: Daniela T B Pereiraderderian, Regina Célia VendraminiAbstract:The spontaneously hypertensive rat (SHR) has an intense consumption of NaCl solution. Water Deprivation (WD) followed by Water intake to satiety induces partial rehydration (PR)—the WD-PR protocol—and sodium appetite. In the present work, WD produced similar Water intake and no alterations in arterial pressure among spontaneously hypertensive rat (SHR), Wistar-Kyoto, and Holtzman strains. It also increased the number of cells with positive c-Fos immunoreactivity (Fos-IR) in the lamina terminalis and in the hypothalamic supraoptic (SON) and paraventricular (parvocellular, PVNp) nucleus in these strains. The WD and WD-PR produced similar alterations in all strains in serum osmolality and protein, plasma renin activity, and sodium balance. The SHR ingested about 10 times more 0.3 M NaCl than normotensives strains in the sodium appetite test that follows WD-PR. After WD-PR, the Fos-IR persisted, elevated in the lamina terminalis of all strains but notably in the subfornical organ of the SHR. The WD-PR reversed Fos-IR in the SON of all strains and in the PVNp of SHR. It induced Fos-IR in the area postrema and in the nucleus of the solitary tract (NTS), dorsal raphe, parabrachial (PBN), pre-locus coeruleus (pre-LC), suprachiasmatic, and central amygdalar nucleus of all strains. This effect was bigger in the caudal-NTS, pre-LC, and medial-PBN of SHRs. The results indicate that WD-PR increases cell activity in the forebrain and hindbrain areas that control sodium appetite in the rat. They also suggest that increased cell activity in facilitatory brain areas precedes the intense 0.3 M NaCl intake of the SHR in the sodium appetite test.
-
Water Deprivation-induced sodium appetite
Physiology & behavior, 2010Co-Authors: Daniela T. B. Pereira-derderian, Regina Célia Vendramini, R.b. DavidAbstract:A Water deprived animal that ingests only Water efficiently corrects its intracellular dehydration, but remains hypovolemic, in negative sodium balance, and with high plasma renin activity and angiotensin II. Therefore, it is not surprising that it also ingests sodium. However, separation between thirst and sodium appetite is necessary to use Water Deprivation as a method to understand the mechanisms subserving sodium appetite. For this purpose, we may use the Water Deprivation-partial repletion protocol, or WD-PR. This protocol allows performing a sodium appetite test after the rat has quenched its thirst; thus, the sodium intake during this test cannot be confounded with a response to thirst. This is confirmed by hedonic shift and selective ingestion of sodium solutions in the sodium appetite test that follows a WD-PR. The separation between thirst and sodium appetite induced by Water Deprivation permits the identification of brain states associated with sodium intake in the appetite test. One of these states relates to the activation of angiotensin II AT1 receptors. Other states relate to cell activity in key areas, e.g. subfornical organ and central amygdala, as revealed by immediate early gene c-Fos immunoreactivity or focal lesions. Angiotensin II apparently sensitizes the brain of the Water deprived rat to produce an enhanced sodium intake, as that expressed by spontaneously hypertensive and by young normotensive rat. The enhancement in sodium intake produced by history of Water Deprivation is perhaps a clue to understand the putative salt addiction in humans. The paper represents an invited review by a symposium, award winner or keynote speaker at the Society for the Study of Ingestive Behavior [SSIB] Annual Meeting in Portland, July 2009.
-
Water Deprivation and the double depletion hypothesis common neural mechanisms underlie thirst and salt appetite
Brazilian Journal of Medical and Biological Research, 2007Co-Authors: L A De Luca, Regina Célia Vendramini, D T B Pereira, Dsda Colombari, Richard B David, Patricia Maria Paula, Jose Vanderlei MenaniAbstract:Water Deprivation-induced thirst is explained by the double-depletion hypothesis, which predicts that dehydration of the two major body fluid compartments, the extracellular and intracellular compartments, activates signals that combine centrally to induce Water intake. However, sodium appetite is also elicited by Water Deprivation. In this brief review, we stress the importance of the Water-depletion and partial extracellular fluid-repletion protocol which permits the distinction between sodium appetite and thirst. Consistent enhancement or a de novo production of sodium intake induced by deactivation of inhibitory nuclei (e.g., lateral parabrachial nucleus) or hormones (oxytocin, atrial natriuretic peptide), in Water-deprived, extracellular-dehydrated or, contrary to tradition, intracellular-dehydrated rats, suggests that sodium appetite and thirst share more mechanisms than previously thought. Water Deprivation has physiological and health effects in humans that might be related to the salt craving shown by our species.
Olivier Lourdais - One of the best experts on this subject based on the ideXlab platform.
-
Water Deprivation compromises maternal physiology and reproductive success in a cold and wet adapted snake vipera berus
Conservation Physiology, 2021Co-Authors: Mathias Dezetter, Jeanfrancois Le Galliard, Gaetan Guiller, Michael Guillon, Mathieu Lerouxcoyau, Sandrine Meylan, Francois Brischoux, Frederic Angelier, Olivier LourdaisAbstract:Abstract Droughts are becoming more intense and frequent with climate change. These extreme weather events can lead to mass mortality and reproduction failure, and therefore cause population declines. Understanding how the reproductive physiology of organisms is affected by Water shortages will help clarify whether females can adjust their reproductive strategy to dry conditions or may fail to reproduce and survive. In this study, we investigated the consequences of a short period of Water Deprivation (2 weeks) during early pregnancy on the physiology and behaviour of a cold- and wet-adapted ectotherm (Vipera berus). We also examined Water allocation to developing embryos and embryonic survival. Water-deprived females exhibited significant dehydration, physiological stress and loss of muscle mass. These effects of Water Deprivation on Water balance and muscle loss were correlated with the number of developing embryos. While Water-deprived females maintained Water transfer to embryos at the expense of their own maintenance, Water Deprivation also led to embryonic mortality. Overall, Water Deprivation amplifies the reproductive costs of Water allocation to support embryonic development. The deleterious impacts of Water Deprivation on female current reproductive performance and on potential survival and future reproduction could lead to severe population declines in this species.
-
Reproductive state and Water Deprivation increase plasma corticosterone in a capital breeder
General and Comparative Endocrinology, 2019Co-Authors: George Brusch, Dale Denardo, Olivier LourdaisAbstract:Plasma corticosterone (CORT) concentrations fluctuate in response to homeostatic demands. CORT is widely recognized as an important hormone related to energy balance. However, far less attention has been given to the potential role of CORT in regulating salt and Water balance or responding to osmotic imbalances. We examined the effects of reproductive and hydric states on CORT levels in breeding Children’s pythons (Antaresia childreni), a species with substantial energetic and hydric costs associated with egg development. Using a 2 × 2 experimental design, we examined how reproduction and Water Deprivation, both separately and combined, impact CORT levels and how these changes correlate with hydration (plasma osmolality) and energy levels (blood glucose). We found that reproduction leads to increased CORT levels, as does dehydration induced by Water Deprivation. The combined impact of reproduction and Water Deprivation led to the largest increases in CORT levels. Additionally, we found significant positive relationships among CORT levels, plasma osmolality, and blood glucose. Our results provide evidence that both reproductive activity and increased plasma osmolality can lead to increased plasma CORT in an ectotherm, which could be explained by either CORT having a role as a mineralocorticoid or CORT being elevated as part of a stress response to resource imbalances.
-
Water Deprivation increases maternal corticosterone levels and enhances offspring growth in the snake Vipera aspis
Journal of Experimental Biology, 2016Co-Authors: Andréaz Dupoué, Francois Brischoux, Frederic Angelier, Dale F. Denardo, Colette Trouvé, Charline Parenteau, Olivier LourdaisAbstract:Circulating glucocorticoid (GC) levels may increase as a result of reproductive effort or in response to unpredictable events. However, GC secretion can vary with the availability of vital trophic resources such as energy. While Water represents another critical resource, the impact of Water Deprivation on GC secretion during reproduction has not yet been thoroughly investigated. Here, we examined the effects of Water Deprivation on plasma corticosterone (CORT) concentrations of female aspic vipers (Vipera aspis), and determined the impacts of Water Deprivation on offspring traits. We exposed both pregnant and non-reproductive females to a 20-day Water Deprivation and compared their pre- and post-Deprivation CORT levels with those of control females. At the end of the treatment, only Water-deprived pregnant females showed a significant increase in CORT levels. In pregnant females, changes in baseline CORT level were correlated with changes in female hydration state. Changes in baseline CORT levels were also negatively influenced by maternal reproductive effort in pregnant control females, while such a relationship was not apparent in pregnant Water-deprived females. Finally, we found that offspring from Water-deprived females had higher growth rates than offspring from control females. Offspring growth was also positively correlated with changes in both maternal osmolality and baseline CORT levels. Together, our results suggest that dehydration increases maternal CORT levels, which may subsequently influence offspring development. Further long-term field studies are therefore required to assess whether there is an adaptive significance of this response.
-
effect of Water Deprivation on baseline and stress induced corticosterone levels in the children s python antaresia childreni
Comparative Biochemistry and Physiology A-molecular & Integrative Physiology, 2014Co-Authors: Olivier Lourdais, Frederic Angelier, Andréaz Dupoué, Xavier Bonnet, Francois BrischouxAbstract:article i nfo Corticosterone(CORT)secretionisinfluencedbyendogenousfactors(e.g.,physiologicalstatus)andenvironmen- tal stressors (e.g., ambient temperature). Heretofore, the impact of Water Deprivation on CORT plasma levels has not been thoroughly investigated. However, both baseline CORT and stress-induced CORT are expected to respondtoWaterDeprivationnotonlybecauseofhydricstressperse,butalsobecauseCORTisanimportantmin- eralocorticoid in vertebrates. We assessed the effects of Water Deprivation on baseline CORT and stress-induced CORT, in Children's pythons (Antaresia childreni), a species that experiences seasonal droughts in natural condi- tions.Weimposeda 52-dayWaterDeprivation ona group of unfedChildren's pythons (i.e.,Water-deprivedtreat- ment) and provided Water ad libitum to another group (i.e., control treatment). We examined body mass variations throughout the experiment, and baseline CORT and stress-induced CORT at the end of the treatments. Relativebodymasslossaveraged~10%inpythonswithoutWater,avalue2to4timeshighercomparedtocontrol snakes. Following re-exposition to Water, pythons from the Water-deprived treatment drank readily and abun- dantly and attained a body mass similar to pythons from the control treatment. Together, these results suggest a substantial dehydration as a consequence of Water Deprivation. Interestingly, stress-induced but not baseline CORT level was significantly higher in Water-deprived snakes, suggesting that baseline CORT might not respond to this degree of dehydration. Therefore, possible mineralocorticoid role of CORT needs to be clarified in snakes. Because dehydration usually induces adjustments (reduced movements, lowered body temperature) to limit Water loss, and decreases locomotor performances, elevated stress-induced CORT in Water-deprived snakes might therefore compensate for altered locomotor performances. Future studies should test this hypothesis.
Mitchell L. Halperin - One of the best experts on this subject based on the ideXlab platform.
-
minimum urine flow rate during Water Deprivation importance of the permeability of urea in the inner medulla
Kidney International, 1998Co-Authors: M Gowrishankar, Ilan Lenga, Surinder Cheemadhadli, Richard Y Cheung, Mitchell L. HalperinAbstract:Minimum urine flow rate during Water Deprivation: Importance of the permeability of urea in the inner medulla. We evaluated whether altering the rate of excretion of sodium (Na) and chloride (Cl) when antidiuretic hormone (ADH) acts would cause urea to behave as an ‘effective' or ‘ineffective' urinary solute. Urine composition was compared to that in the excised papillary tip in rats treated with DDAVP while on a normal or a low electrolyte diet; half the rats were given a urea load. Studies were also carried out in humans who were Water restricted for 12 to 16 hours and given DDAVP. One group had a high rate of NaCl excretion induced by a thiazide diuretic, while the other group consumed a low salt diet to decrease the rate of excretion of electrolytes. Urea (3 mmol/kg) was ingested after the control urine samples were collected. On the high salt protocols, the urine flow rate was directly proportional to the rate of excretion of electrolytes (‘non-urea' osmoles) and there was no change in the ‘non-urea' osmolality despite large changes in Na and Cl excretion rates. After urea was administered, there was no change in urine flow rate, ‘non-urea' osmolality, or ‘non-urea' osmole excretion rate, whereas the urinary urea concentration, urine osmolality and the rate of excretion of urea were higher. The papilla of the salt-loaded rats had a similar urea concentration to that in the urine. In contrast, in the low electrolyte excretion protocols, the sum of the concentrations of ‘non-urea' osmoles in the urine was much lower than that in the excised papilla, and the converse applied to urea. Similar changes were observed in the composition of the urine in human subjects with high and low rates of excretion of electrolytes. We conclude that urea appears to be an ‘ineffective' urine osmole when there is a high rate of salt excretion, whereas urea is an ‘effective' osmole when there is a low rate of excretion of electrolytes.
-
minimum urine flow rate during Water Deprivation importance of the nonurea versus total osmolality in the inner medulla
Journal of The American Society of Nephrology, 1997Co-Authors: Steven Demetri Soroka, Sirithon Chayaraks, Jeffrey Myers, Stanley I Rubin, Henrik Sonnenberg, Surinder Cheemadhadli, Mitchell L. HalperinAbstract:Antidiuretic hormone leads to an increase in the permeability for Water and urea in the inner medullary collecting duct. Hence, urea may not be an "effective" osmole in the inner medulla during maximal renal Water conservation. Accordingly, the purpose of this study was to evaluate whether differences in the rate of urea excretion would influence maximum renal Water conservation in humans. In Water-deprived rats, the concentration of urea and total osmolality were somewhat higher in the urine exiting the inner medullary collecting duct than in interstitial fluid obtained from the entire papillary tip. Nevertheless, the "nonurea" (total osmolality minus urea in millimolar terms) osmolality was virtually identical in both locations. Chronically fasted human subjects that were Water-deprived for 16 h had a lower rate of urea excretion (71 +/- 7 versus 225 +/- 14 mumol/min) and a somewhat lower urine osmolality (745 +/- 53 versus 918 +/- 20 mosmol/kg H2O). Nevertheless, they had identical urine flow rates (0.5 +/- 0.01 and 0.5 +/- 0.02 ml/min, respectively), and their nonurea osmolality also was similar (587 +/- 25 and 475 +/- 14 mosmol/kg H2O, respectively) to the Water-deprived normal subjects. The composition of their urine differed in that the principal nonurea osmoles became NH4+ and beta-hydroxybutyrate rather than Na and C1. During Water Deprivation in normal subjects, the ingestion of urea caused a twofold rise in urine flow rate, a fall in the nonurea osmolality, and a rise in the rate of excretion of nonurea osmoles. The nonurea osmolality of the urine, and presumably the medullary interstitial fluid as well, was inversely related to the urea excretion rate. In chronic fasting, the nature, but not the quantity, of nonurea osmoles changed. The similar minimum urine volume was predictable from an analysis based on nonurea osmole considerations.
