Potentiation by endothelin-1 and vasopressin of sympathetic vasoconstriction in male and female rats

2002 ◽  
Vol 103 (s2002) ◽  
pp. 158S-161S ◽  
Author(s):  
Nuria FERNÁNDEZ ◽  
Elena SANZ ◽  
Luis MONGE ◽  
María Angeles MARTÍNEZ ◽  
Godofredo DIÉGUEZ ◽  
...  
Keyword(s):  
Electrical Field Stimulation ◽  
Female Rats ◽  
Male Rats ◽  
Electrical Field ◽  
Endothelin 1 ◽  
Male And Female Rats ◽  
Sympathetic Vasoconstriction ◽  
Arterial Contraction ◽  
Rat Tail

The aim of this study was to analyse the modulatory role of endothelin-1 and vasopressin in sympathetic vasoconstriction, and whether there are gender differences in this modulatory role. Electrical field stimulation (4Hz, 0.2ms pulse duration at supramaximal voltage of 70V, for 1s), applied to isolated segments from rat tail arteries, produced a contraction that was lower in the vascular segments from female than in those from male rats. This arterial contraction was potentiated in a concentration-dependent way by endothelin-1 (10-10–3×10-9mol/l) and vasopressin (10-12–10-10mol/l), and the increment produced by endothelin-1 was similar in the arteries of both, whereas the increment induced by vasopressin was higher in the arteries from male than in those from female rats. These results suggest that endothelin-1 and vasopressin potentiate the vasoconstriction to sympathetic stimulation, and this potentiating effect of vasopressin may be higher, whereas that of endothelin-1 may be similar, in males than in females.

scholarly journals Sex Differences in Demand for Highly Palatable Foods: Role of the Orexin System

2020 ◽  
Author(s):  
Linnea R Freeman ◽  
Brandon S Bentzley ◽  
Morgan H James ◽  
Gary Aston-Jones
Keyword(s):  
Sex Differences ◽  
Demand Curve ◽  
Female Rats ◽  
Demand Elasticity ◽  
Male Rats ◽  
Neural Activation ◽  
Palatable Food ◽  
Behavioral Economic ◽  
Male And Female Rats

Abstract Background The prevalence of eating disorders, including binge eating disorder, is significantly higher in women. These findings are mirrored by preclinical studies, which indicate that female rats have a higher preference for palatable food and show greater binge-like eating compared with male rats. Methods Here, we describe a novel within-session behavioral-economic paradigm that allows for the simultaneous measurement of the intake at null cost (Q0) and normalized demand elasticity (α) of 3 types of palatable food (low fat, high fat, and chocolate sucrose pellets) via demand curve analysis. In light of evidence that the orexin (hypocretin) system is critically involved in reward and feeding behaviors, we also examined the role of orexin function in sex differences of economic demand for palatable foods. Results The novel within-session behavioral-economic approach revealed that female rats have higher intake (demand) than males for all palatable foods at low cost (normalized to body weight) but no difference in intake at higher prices, indicating sex-dependent differences in the hedonic, but not motivational, aspects of palatable food. Immediately following behavioral-economic testing, we observed more orexin-expressing neurons and Fos expression (measure of recent neural activation) in these neurons in female rats compared with male rats. Moreover, the orexin-1 receptor antagonist SB334867 reduced both low- and high-cost intake for palatable food in both male and female rats. Conclusions These findings provide evidence of higher demand at low prices for palatable food in females and indicate that these behavioral differences may be associated with sexual dimorphism in orexin system function.

γ-Aminobutyric acid regulation of neurohypophysial hormone secretion in male and female rats

1989 ◽  
Vol 121 (2) ◽  
pp. 343-349 ◽  
Author(s):  
E. Saridaki ◽  
D. A. Carter ◽  
S. L. Lightman
Keyword(s):  
Hormone Secretion ◽  
Model Systems ◽  
Female Rats ◽  
Aminobutyric Acid ◽  
Male Rats ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Endogenous Gaba ◽  
Male And Female Rats

ABSTRACT The role of γ-aminobutyric acid (GABA) in the control of oxytocin and arginine vasopressin (AVP) release from the posterior pituitary was investigated using the GABA agonist muscimol and the GABA antagonists bicuculline and picrotoxin. Two perifusion model systems were studied using (a) intact isolated posterior pituitaries (IPP) and (b) neurosecretosomes from both male and female rats. In experiments on tissue from male rats, the stimulated release of oxytocin and AVP in both models was inhibited by muscimol, an effect which was reversed in the presence of bicuculline. Bicuculline alone increased the release of oxytocin only. Although similar responses to muscimol or bicuculline were seen in neurosecretosomes from female animals, neither agent affected oxytocin and AVP release from the intact IPP. Picrotoxin had a similar effect to bicuculline on oxytocin in isolated posterior pituitaries from male as well as female rats, although at the neurosecretosome level a paradoxical inhibition was observed. These results provide evidence for an endogenous GABA receptor mechanism at the level of the neurosecretory terminals in both male and female rats. The sexually dimorphic IPP response suggests a second more complex mechanism involving either pituicytenerve terminal interactions and/or a secondary role of other neurotransmitters in the GABA regulation of neurohypophysial hormones. Journal of Endocrinology (1989) 121, 343–349

Effects of sex and exercise training on β-adrenoreceptor mediated opposition of evoked sympathetic vasoconstriction in resting and contracting muscle of rats

2020 ◽  
Author(s):  
Ian R. Cooper ◽  
Sixue Liu ◽  
Darren S. DeLorey
Keyword(s):  
Exercise Training ◽  
Triceps Surae ◽  
Female Rats ◽  
Male Rats ◽  
Sprague Dawley ◽  
Contracting Muscle ◽  
Arterial Blood ◽  
Male And Female Rats ◽  
Sympathetic Vasoconstriction ◽  
Main Effect

This study investigated the hypothesis that β-adrenoreceptor mediated inhibition of sympathetic vasoconstriction would be enhanced in female compared to male rats, and that exercise training would augment β-adrenoreceptor inhibition of sympathetic vasoconstriction in male and female rats. Sprague-Dawley rats were randomized into sedentary (Male: n=7; Female: n=8) and exercise trained (Male: n=9; Female: n=9) groups. Following 4 weeks of exercise training or sedentary behavior, rats were anesthetized and surgically instrumented for stimulation of the lumbar sympathetic chain, muscle contraction and measurement of arterial blood pressure and femoral artery blood flow (FBF). Femoral vascular conductance (FVC) was calculated as FBF/mean arterial pressure. The percentage change of FVC in response to sympathetic stimulation delivered at 2 and 5 Hz was measured at rest and during contraction of the triceps surae muscles before and after β-adrenoreceptor blockade (Propranolol;0.075 mg·kg-1, IV). We found that, at rest, β-adrenoreceptor blockade decreased (main effect of drug, 2Hz: P <0.001; 5Hz: P<0.001) sympathetic vasoconstriction. During contraction, sympathetic vasoconstrictor responsiveness was lower (main effect of sex, 2Hz: P=0.001; 5Hz: P=0.023) in female compared to male rats, and sympatholysis was enhanced (main effect of sex, 2 Hz: P=0.001; 5Hz: P<0.001) in female rats. β-adrenoreceptor blockade decreased (main effect of drug, 2Hz: P=0.049; 5Hz: P<0.001) evoked sympathetic vasoconstriction in contracting muscle. The present study demonstrated that β-adrenoreceptors do not blunt sympathetic vasoconstriction in resting or contracting skeletal muscle of male or female rats. Sympatholysis was enhanced in female rats, however, this was not attributable to β-adrenoreceptor mediated blunting of sympathetic vasoconstriction.

Effects of mineralocorticoids and glucocorticoids on compensatory adrenal growth in rats

1985 ◽  
Vol 248 (4) ◽  
pp. E450-E456 ◽  
Author(s):  
R. Phillips ◽  
C. Crock ◽  
J. Funder
Keyword(s):  
Adrenal Gland ◽  
Compensatory Growth ◽  
Adrenal Glands ◽  
Pituitary Hormones ◽  
Female Rats ◽  
Male Rats ◽  
Unilateral Adrenalectomy ◽  
Male And Female ◽  
Male And Female Rats

The rapid compensatory growth seen in the remaining adrenal gland of the rat after unilateral adrenalectomy appears to require a functioning neural arc between the adrenal glands and the hypothalamus, but the role of adrenal or pituitary hormones is unclear. We have examined the effect of several steroids on the compensatory adrenal growth (CAG). Female and male rats (average wt 140 g) were unilaterally adrenalectomized and treated with aldosterone (2.1 micrograms/day), corticosterone (B, 28 micrograms/day), dexamethasone (28 micrograms/day), 9 alpha-fluorocortisol (9 alpha FC, 28 micrograms/day), or deoxycorticosterone (DOC, 28 micrograms/day) by continuous infusion for 3 days and then killed. The growth in the remaining adrenal was compared both with sham-operated rats treated with steroid infusions and with noninfused controls. In rats of this size females have larger adrenals than males; untreated male rats have significantly heavier left than right adrenals. In male rats the extent of CAG after no treatment or treatment with aldosterone B, 9 alpha FC, or DOC depended on the size of the adrenal gland removed. In both male and female rats CAG was not significantly affected by aldosterone, in contrast with a recent report, nor by B, 9 alpha FC, or DOC; no significant CAG was seen after dexamethasone. Taken together, these results and previous reports suggest that neurally mediated activation of pituitary and/or local adrenal growth factors may be responsible for CAG.

scholarly journals ALCOHOL ABOLISHES POST-STRESSOR AVERSION IN MALE RATS (POTENTIAL ROLE OF к-OPIOID RECEPTORS)

2018 ◽  
Vol 18 (1) ◽  
pp. 77-83
Author(s):  
V N Mukhin ◽  
A P Kozlov ◽  
I N Abdurasulova ◽  
K I Pavlov ◽  
V V Sizov ◽  
...  
Keyword(s):  
Opioid Receptors ◽  
Preference Test ◽  
Reward System ◽  
Female Rats ◽  
Male Rats ◽  
Final Conclusion ◽  
Alcohol Administration ◽  
Male And Female Rats ◽  
Stimulation Of

The probability of alcohol consumption by humans and experimental animals increases immediately after impact of stressors and remains at high level for some time. Neurobiological basis of this pattern is the effect of stress hormones on the mesolimbic system which is the core of the reward system in the brain that initiates learning processes. Literature data suggest that formation of aversive reactions depends on the system of dynorphin and к-opioid receptors which activates during the stress reaction. The purpose of this study was to investigate effect of alcohol administration on the post-stressor condition of the reward system and to clarify the role of к-opioid receptors in this. Experiment 1 aimed to investigation of post-stressor condition of the reward system in male and female rats and the influence of alcohol administration on it. Experiment 2 aimed to study whether alcohol affects the known from the literature aversive effect of che mical stimulation of к-opioid receptors as a model of post-stressor aversion. Methods. Appearance of preference or aversion to place where the rats were after action of the stressor was the indicator of the state of their reward syste m (place preference test). Result of the experiment 1. Condition of the reward syste m in the male rats was aversive 15 minutes after the end of the stressor action that caused avoidance of the context of environment in the future. Administration of alcohol after the end of the stressor action ceased this effect. Result of the experiment 2. Unlike the post-stressor aversion alcohol does not influence the aversion caused by stimulation of к-opioid receptors. Conclusion. Results of the study suggest that there is the aversive phase of the post-stressor state in the male rats that leads to formation of aversive associative reaction to the context of environment. Alcohol administration abolishes this phase. The involve ment of к- opioid receptors in this effect of alcohol is doubtful. But the final conclusion is possible only after direct experiment using antagonists.

Liver glycogenolysis during exercise in adrenodemedullated male and female rats

1986 ◽  
Vol 251 (6) ◽  
pp. R1151-R1155
Author(s):  
W. W. Winder ◽  
S. F. Loy ◽  
D. S. Burke ◽  
S. J. Hawkes
Keyword(s):  
Adrenergic Receptor ◽  
Mature Female ◽  
Female Rats ◽  
Male Rats ◽  
Plasma Epinephrine ◽  
Male And Female ◽  
Male And Female Rats ◽  
Liver Glycogenolysis ◽  
Stimulation Of

Previous studies have shown that adrenodemedullation has no effect on the rate of liver glycogenolysis during exercise in male rats. Mature female rats have been reported to have a higher hepatic beta-adrenergic receptor activity than do male rats of the same age. The present study was undertaken to determine the role of plasma epinephrine in stimulating liver glycogenolysis during exercise in female rats. Both male and female rats were adrenodemedullated or sham operated. Three weeks later rats were run for 60 min at 21 m/min up a 15% grade. The rate of liver glycogenolysis during exercise was not affected by adrenodemedullation in either female rats or male rats. Hepatic adenosine 3',5'-cyclic monophosphate increased to approximately the same extent in sham operated as in adrenodemedullated female rats during exercise. Adrenodemedullation caused a significant reduction in the amount of glycogen utilized by the soleus muscle and in the degree of hyperglycemia during exercise. We conclude that epinephrine is unessential for stimulation of liver glycogenolysis during exercise in either male or female rats.

scholarly journals Role of endogenous endothelin-1 in catecholamine secretion induced by electrical field stimulation from the isolated perfused rat adrenal gland

1999 ◽  
Vol 79 ◽  
pp. 125
Author(s):  
Takahiro Nagayama ◽  
Takayuki Matsumoto ◽  
Fumiyo Kuwakubo ◽  
Yasuo Matsumura ◽  
Hiroaki Hisa ◽  
...  
Keyword(s):  
Adrenal Gland ◽  
Electrical Field Stimulation ◽  
Catecholamine Secretion ◽  
Field Stimulation ◽  
Electrical Field ◽  
Endothelin 1

scholarly journals Sex-specific effects of neonatal progestin receptor antagonism on juvenile social behavior in rats.

2021 ◽  
Author(s):  
Robin M Forbes-Lorman
Keyword(s):  
Sex Differences ◽  
Brain Regions ◽  
Female Rats ◽  
Male Rats ◽  
Postnatal Life ◽  
Social Discrimination ◽  
Specific Effects ◽  
Male And Female Rats ◽  
Brain And Behavior

Abstract Developing mammals are exposed to progesterone through several sources; however, the role of progesterone in early development is not well understood. Males express more progestin receptors (PRs) than females within several brain regions during early postnatal life, suggesting that PRs may be important for the organization of the sex differences in the brain and behavior. Indeed, previous studies showed cognitive impairments in male rats treated neonatally with a PR antagonist. In the present study, we examined the role of PRs in organizing juvenile behaviors. Social play behavior and social discrimination were examined in juvenile male and female rats that had been treated with CDB, a PR antagonist, during the first week of postnatal life. Interestingly, neonatal PR antagonism altered different juvenile behaviors in males and females. A transient disruption in PR signaling during development had no effect on social discrimination but increased play initiation and pins in females. These data suggest that PRs play an important role in the organization of sex differences in some social behaviors.

scholarly journals Role of endothelin-1 antagonist; bosentan, against cisplatin-induced nephrotoxicity in male and female rats

2015 ◽  
Vol 4 (1) ◽  
pp. 83 ◽  
Author(s):  
Mehdi Nematbakhsh ◽  
Maryam Moeini ◽  
Ardeshir Talebi ◽  
Zahra Jokar
Keyword(s):  
Female Rats ◽  
Male And Female ◽  
Endothelin 1 ◽  
Male And Female Rats
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