Thermal dehydration-induced thirst in rats: role of body temperature

1995 ◽  
Vol 269 (3) ◽  
pp. R557-R564 ◽  
Author(s):  
C. C. Barney ◽  
M. M. Folkerts
Keyword(s):  
Body Temperature ◽  
Core Temperature ◽  
Water Intake ◽  
Thermal Dehydration ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Access To Water

Male Sprague-Dawley rats were used to study the possible role of hyperthermia in the thirst associated with thermal dehydration. Rats were exposed to 40 degrees C for 4 h and then allowed access to water at different times after they were transferred to 25 degrees C. Delaying the time prior to allowing the rats to drink did not significantly alter either water intake or percent rehydration even though core temperature decreased during the first 1.5 h after removal from the heat. Exposing thermally dehydrated rats to 5 degrees C for 30 min prior to allowing them access to water also failed to significantly affect water intake or percent rehydration. Thermally dehydrated rats allowed to drink while remaining in the heat did not show a significant increase in water intake during the first hour or percent rehydration over rats drinking at 25 degrees C. Nondehydrated rats did show significant increases in water intake and percent rehydration when allowed to drink in the heat. Hyperthermia does not play a role in drinking in thermally dehydrated rats but can stimulate drinking in water-replete rats.

Thermal dehydration-induced thirst in rats: role of angiotensin II

1991 ◽  
Vol 261 (5) ◽  
pp. R1171-R1175 ◽  
Author(s):  
C. C. Barney ◽  
J. S. Williams ◽  
D. H. Kuiper
Keyword(s):  
Angiotensin Ii ◽  
Water Intake ◽  
Water Deprivation ◽  
Physiological Responses ◽  
Heat Exposure ◽  
Plasma Renin ◽  
Thermal Dehydration ◽  
Converting Enzyme ◽  
Sprague Dawley

Dehydration can be brought about by either water deprivation or by heat exposure (thermal dehydration). Angiotensin II has been shown to have a role in water deprivation-induced thirst. The current study was designed to determine whether angiotensin II is involved in thirst caused by thermal dehydration. Male Sprague-Dawley strain rats were dehydrated by exposure to a 40 degree C environment for 2-4 h or by water deprivation for 44 h. Water deprivation but not heat exposure significantly increased plasma renin activity. Neither ureteric ligation nor nephrectomy significantly altered water intake after thermal dehydration. Captopril, an inhibitor of angiotensin converting enzyme, given at a dose of 100 mg/kg ip, significantly decreased water intake in water-deprived rats but not in thermally dehydrated rats. Angiotensin II therefore does not appear to play a role in the control of water intake of thermally dehydrated rats. The physiological responses to dehydration in rats are dependent on the way in which the dehydration is brought about.

Role of prostaglandins in exercise-induced core temperature elevation in female Sprague-Dawley rats

1993 ◽  
Vol 265 (5) ◽  
pp. R1121-R1125
Author(s):  
P. J. Rowsey ◽  
K. T. Borer ◽  
M. J. Kluger
Keyword(s):  
Body Temperature ◽  
Sodium Salicylate ◽  
Voluntary Exercise ◽  
Female Rats ◽  
Temperature Elevation ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Exercise Induced ◽  
Running Wheels

Female Sprague-Dawley rats (12:12-h photoperiod; body temperature, BT, measured with biotelemetry) with access to running wheels for 6 wk have an elevated BT (compared with rats with no access to exercise wheels, i.e, sedentary) both during the period of voluntary exercise (nighttime) (0.5 degree C, P = 0.0001) and the nonexercise period (daytime) (0.3 degree C, P = 0.002). To determine whether prostaglandin (PG) E was responsible for any portion of this daytime rise in BT, we injected a dose of sodium salicylate (300 mg/kg), which was shown to produce complete antipyresis in rats injected with lipopolysaccharide (LPS), into exercised and sedentary rats 4 h after the onset of the lights-on period. The injections of sodium salicylate led to a fall in body temperature in both the exercised and sedentary rats of similar amounts (-0.88 degree C vs. -0.61 degree C at 2 h postinjection, P = 0.59). We conclude that the increase in daytime BT of exercised female rats is not mediated by prostaglandins.

scholarly journals Effect of body temperature during exercise on skeletal muscle cytochrome c oxidase content

2002 ◽  
Vol 93 (2) ◽  
pp. 526-530 ◽  
Author(s):  
Christopher R. Mitchell ◽  
M. Brennan Harris ◽  
Anthony R. Cordaro ◽  
Joseph W. Starnes
Keyword(s):  
Body Temperature ◽  
Cytochrome C ◽  
Cytochrome C Oxidase ◽  
Extensor Digitorum Longus ◽  
Extensor Digitorum ◽  
Sprague Dawley ◽  
Ambient Temperatures ◽  
Sprague Dawley Rats ◽  
Mitochondrial Heat Shock Protein

This study determined the role of body temperature during exercise on cytochrome- c oxidase (CytOx) activity, a marker of mitochondrial content, and mitochondrial heat shock protein 70 (mtHSP70), which is required for import of nuclear-coded preproteins. Male, 10-wk-old, Sprague-Dawley rats exercised identically for 9 wk in ambient temperatures of 23°C ( n = 10), 8°C with wetted fur ( n = 8), and 4°C with wetted fur and fan ( n = 7). These conditions maintained exercising core temperature (Tc) at 40.4, 39.2, or 38.0°C (resting temperature), respectively. During weeks 3–9, exercisers ran 5 days/wk up a 6% grade at 20 m/min for 60 min. Animals were housed at 23°C. Gastrocnemius CytOx activity in Tc=38.0°C (83.5 ± 5.5 μatoms O · min−1 · g wet wt−1) was greater than all other groups ( P< 0.05), exceeding sedentary ( n = 7) by 73.2%. Tc of 40.4 and 39.2°C also were higher than sedentary by 22.4 and 37.4%, respectively ( P < 0.05). Quantification of CytOx content verified that the increased activity was due to an increase in protein content. In extensor digitorum longus, a nonactive muscle, CytOx was not elevated in Tc = 38.0°C. mtHSP70 was significantly elevated in gastrocnemius of Tc = 38.0°C compared with sedentary ( P < 0.05) but was not elevated in extensor digitorum longus ( P > 0.05). The data indicate that decreasing exercise Tc may enhance mitochondrial biogenesis and that mtHSP70 expression is not dependent on temperature.

scholarly journals Mild DOCA-salt hypertension: sympathetic system and role of renal nerves

2011 ◽  
Vol 300 (5) ◽  
pp. H1781-H1787 ◽  
Author(s):  
Sachin S. Kandlikar ◽  
Gregory D. Fink
Keyword(s):  
Control Period ◽  
Whole Body ◽  
Renal Nerves ◽  
Experimental Hypertension ◽  
Sympathetic Activation ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Salt Hypertension ◽  
Hypertension Development

Excess sympathetic nervous system activity (SNA) is linked to human essential and experimental hypertension. To test whether sympathetic activation is associated with a model of deoxycorticosterone acetate (DOCA)-salt hypertension featuring two kidneys and a moderate elevation of blood pressure, we measured whole body norepinephrine (NE) spillover as an index of global SNA. Studies were conducted in chronically catheterized male Sprague-Dawley rats drinking water containing 1% NaCl and 0.2% KCl. After a 7-day surgical recovery and a 3-day control period, a DOCA pellet (50 mg/kg) was implanted subcutaneously in one group of rats (DOCA), while the other group underwent sham implantation (Sham). NE spillover was measured on control day 2 and days 7 and 14 after DOCA administration or sham implantation. During the control period, mean arterial pressure (MAP) was similar in Sham and DOCA rats. MAP was significantly increased in the DOCA group compared with the Sham group after DOCA administration ( day 14: Sham = 109 ± 5.3, DOCA = 128 ± 3.6 mmHg). However, plasma NE concentration, clearance, and spillover were not different in the two groups at any time. To determine whether selective sympathetic activation to the kidneys contributes to hypertension development, additional studies were performed in renal denervated (RDX) and sham-denervated (Sham-DX) rats. MAP, measured by radiotelemetry, was similar in both groups during the control and DOCA treatment periods. In conclusion, global SNA is not increased during the development of mild DOCA-salt hypertension, and fully intact renal nerves are not essential for hypertension development in this model.

Chronic intravenous administration of V1 arginine vasopressin agonist results in sustained hypertension

1994 ◽  
Vol 267 (2) ◽  
pp. H751-H756 ◽  
Author(s):  
A. W. Cowley ◽  
E. Szczepanska-Sadowska ◽  
K. Stepniakowski ◽  
D. Mattson
Keyword(s):  
Body Weight ◽  
Arginine Vasopressin ◽  
Plasma Catecholamines ◽  
Plasma Osmolality ◽  
Sprague Dawley ◽  
Prolonged Administration ◽  
Chronic Stimulation ◽  
Sustained Hypertension ◽  
Sprague Dawley Rats

Despite the well-recognized vasoconstrictor and fluid-retaining actions of vasopressin, prolonged administration of arginine vasopressin (AVP) to normal animals or humans fails to produce sustained hypertension. The present study was performed to elucidate the role of the V1 receptor in determining the ability of AVP to produce sustained hypertension. Conscious Sprague-Dawley rats with implanted catheters were infused with the selective V1 agonist, [Phe2,Ile3,Orn8]vasopressin (2 ng.kg-1.min-1), for 14 days in amounts that were acutely nonpressor. Blood pressure (MAP), heart rate (HR), body weight, and water intake (WI) were determined daily. Plasma AVP, plasma catecholamines norepinephrine and epinephrine, plasma osmolality, and electrolyte concentration were determined before and on days 1 and 7 of infusion. MAP increased significantly by 10.4 +/- 4.5 mmHg on day 1 and rose to 22 +/- 5 mmHg above control by day 14 (transient decrease on days 6-9) and then fell to control levels after the infusion was stopped. HR did not change significantly. Plasma AVP immunoreactivity increased from 2.5 +/- 0.3 to 10.9 +/- 2.1 pg/ml, whereas norepinephrine tended to fall only on day 1, with epinephrine only slightly elevated on day 7. No evidence of fluid retention was found, and rats lost sodium only on the first day of V1 agonist infusion. Body weight increased throughout the study but was unrelated to the changes of MAP. We conclude that chronic stimulation of V1 receptors results in sustained hypertension in rats.

The Hepatoprotective Role of Warburgia salutaris and Iso-Mukaadial Acetate on Carbon tetrachloride Intoxicated Rats Model

2021 ◽  
Vol 17 ◽  
Author(s):  
Gideon Ayeni ◽  
Mthokozisi Blessing Cedric Simelane ◽  
Shahidul Islam ◽  
Ofentse Jacob Pooe
Keyword(s):  
Carbon Tetrachloride ◽  
Hepatic Injury ◽  
Antioxidant Properties ◽  
Hepatic Necrosis ◽  
Protective Role ◽  
Dependent Manner ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Isolated Compound

Background: Medicinal plants together with their isolated bioactive compounds are known for their antioxidant properties which constitute therapeutic agents that are routinely employed in the treatment of liver diseases. Aims of the Study: The current study sought to explore the protective role of Warburgia salutaris and its isolated compound, iso-mukaadial acetate against carbon tetrachloride (CCl4)-induced hepatic injury. Methods: Thirty-five male Sprague Dawley rats were divided into seven groups of five animals each and injected with CCl4 to induce hepatic injury. Results: Treatment with the crude extract of W. salutaris and of iso-mukaadial acetate significantly reduced the levels of alkaline phosphatase, alanine and aspartate aminotransaminases, total bilirubin and malondialdehyde in a dose dependent manner, when compared to untreated groups. Liver histology revealed a reduction in hepatic necrosis and inflammation. Conclusion: The current investigation has demonstrated that W. salutaris extract and iso-mukaadial acetate could mitigate the acute liver injury inflicted by a hepatotoxic inducer in rats.

scholarly journals Transient Neonatal Cryptosporidium parvum Infection Triggers Long-Term Jejunal Hypersensitivity to Distension in Immunocompetent Rats

2006 ◽  
Vol 74 (7) ◽  
pp. 4387-4389 ◽  
Author(s):  
Rachel Marion ◽  
Asiya Baishanbo ◽  
Gilles Gargala ◽  
Arnaud François ◽  
Philippe Ducrotté ◽  
...  
Keyword(s):  
Cryptosporidium Parvum ◽  
Myeloperoxidase Activity ◽  
Sprague Dawley ◽  
Depressor Response ◽  
Sprague Dawley Rats

ABSTRACT In 5-day-old immunocompetent Sprague-Dawley rats infected with either 102 or 105 Cryptosporidium parvum oocysts, transient infection resulted 120 days later in increased cardiovascular depressor response to jejunal distension and jejunal myeloperoxidase activity (P < 0.05). Nitazoxanide treatment normalized jejunal sensitivity (P < 0.001) but not myeloperoxidase levels (P > 0.05). Data warrant further evaluation of the role of early cryptosporidiosis in the development of chronic inflammatory gut conditions.

Recombinant human regenerating gene 4 attenuates the severity of osteoarthritis by promoting the proliferation of articular chondrocyte in an animal model

2021 ◽  
Vol 14 ◽  
Author(s):  
Xue-jia Li ◽  
Fei Zhu ◽  
Bo Li ◽  
Dong Zhang ◽  
Cheng-Wei Liang
Keyword(s):  
Risk Factors ◽  
Animal Model ◽  
Sprague Dawley ◽  
Articular Chondrocyte ◽  
Chondrocyte Proliferation ◽  
Histological Changes ◽  
Proper Role ◽  
Sprague Dawley Rats ◽  
Gene 4

Introduction: Osteoarthritis (OA) is a dominant cause of morbidity and disability. As a chronic disease, its etiological risk factors and most therapies at present, are empirical and symptomatic. Regenerating gene 4 (Reg4) is involved in cell growth, survival, regeneration, adhesion, and resistance to apoptosis, which are partially thought to be the pathogenic mechanisms of OA. However, the proper role of Reg4 in OA is still unknown. Methods: In this study, a consecutive administration of rhReg4 was applied to normal Sprague-Dawley rats or rats after OA induction. Histological changes and chondrocyte proliferation in the articular cartilage were measured. Results: We found that RhReg4 promotes chondrocyte proliferation in normal rats, and RhReg4 attenuated the severity of OA in rats by promoting chondrocytes’ proliferation in OA rats. Conclusion: In conclusion, recombinant human regenerating gene 4 (rhReg4) attenuates the severity of osteoarthritis in OA animal models and may be used as a new method for the treatment of osteoarthritis.

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