Sex differences in behavioural androgen sensitivity: possible role of androgen metabolism

1984 ◽  
Vol 100 (2) ◽  
pp. 245-248 ◽  
Author(s):  
A. Mode ◽  
J.-Å. Gustafsson ◽  
P. Södersten ◽  
P. Eneroth
Keyword(s):  
Sex Difference ◽  
Sexual Behaviour ◽  
Behavioural Response ◽  
Female Rats ◽  
Male Rats ◽  
Androgen Metabolism ◽  
Target Organs ◽  
Androgen Sensitivity ◽  
Masculine Sexual Behaviour

ABSTRACT Masculine sexual behaviour was induced in castrated sexually inactive but experienced male rats by testosterone-filled constant-release implants or daily injections of the synthetic androgen 17β-hydroxy-17α-methyl-estra-4,9,11-triene-3-one (methyltrienolone, R 1881), which resists metabolism by target organs. Feminization of the hepatic androgen metabolism by subcutaneous implantation of osmotic minipumps, which delivered a constant amount of human GH, did not affect the behavioural response of castrated rats to testosterone. Testosterone implants were only minimally effective in inducing male behaviour in ovariectomized female rats, but R 1881 was as effective in stimulating male behaviour in females as in males. Testosterone-treated but not R 1881-treated females showed pronounced female sexual behaviour in response to progesterone treatment despite the absence of measureable amounts of oestradiol-17β in peripheral blood. The results provide evidence that masculine sexual behaviour can be activated by an androgen in the absence of oestrogenic stimulation and suggest that the sex difference in the behavioural response to testosterone may be due to a sex difference in the metabolism of androgens by the brain. J. Endocr. (1984) 100, 245–248

scholarly journals Role of Ventromedial Hypothalamus in Sucrose-Induced Obesity on Metabolic Parameters

2021 ◽  
pp. 097275312110057
Author(s):  
Archana Gaur ◽  
G.K. Pal ◽  
Pravati Pal
Keyword(s):  
Insulin Resistance ◽  
Weight Gain ◽  
Food Intake ◽  
Ventromedial Hypothalamus ◽  
Female Rats ◽  
Metabolic Parameters ◽  
Male Rats ◽  
Significant Weight Gain ◽  
The Metabolic Syndrome

Background: Obesity is because of excessive fat accumulation that affects health adversely in the form of various diseases such as diabetes, hypertension, cardiovascular diseases, and many other disorders. Our Indian diet is rich in carbohydrates, and hence the sucrose-induced obesity is an apt model to mimic this. Ventromedial hypothalamus (VMH) is linked to the regulation of food intake in animals as well as humans. Purpose: To understand the role of VMHin sucrose-induced obesity on metabolic parameters. Methods: A total of 24 adult rats were made obese by feeding them on a 32% sucrose solution for 10 weeks. The VMH nucleus was ablated in the experimental group and sham lesions were made in the control group. Food intake, body weight, and biochemical parameters were compared before and after the lesion. Results: Male rats had a significant weight gain along with hyperphagia, whereas female rats did not have a significant weight gain inspite of hyperphagia. Insulin resistance and dyslipidemia were seen in both the experimental and control groups. Conclusion: A sucrose diet produces obesity which is similar to the metabolic syndrome with insulin resistance and dyslipidemia, and a VMH lesion further exaggerates it. Males are more prone to this exaggeration.

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.

Sex Differences in Cholinergic Analgesia I 

1999 ◽  
Vol 91 (5) ◽  
pp. 1447-1447 ◽  
Author(s):  
Astrid Chiari ◽  
Joseph R. Tobin ◽  
Hui-Lin Pan ◽  
David D. Hood ◽  
James C. Eisenach
Keyword(s):  
Sex Difference ◽  
Intrathecal Administration ◽  
Female Rats ◽  
Male Rats ◽  
Muscarinic Agonist ◽  
Noxious Heat ◽  
Male And Female Rats ◽  
Adrenergic Antagonist ◽  
Cholinergic Agents ◽  
Dose Dependent

Background Cholinergic agents produce analgesia after systemic and intrathecal administration. A retrospective review showed that intrathecal neostigmine was more potent in women than in men, suggesting a sex difference in this response. The purpose of this study was to determine whether such a sex difference exists in normal rats and to examine the pharmacologic mechanisms that underlie this difference. Methods Male and female rats with indwelling intrathecal catheters received injections of neostigmine, bethanechol (muscarinic agonist), or RJR-2403 (neuronal nicotinic agonist) alone or with atropine (muscarinic antagonist), mecamylamine (nicotinic antagonist), or phentolamine alpha-adrenergic antagonist) with antinociception determined to a noxious heat stimulus to the hind paw. Time versus subcutaneous paw temperature relationships were defined for males and females. Results Neostigmine produced dose-dependent antinociception with five times greater potency in female than in male rats. Neostigmine-induced antinociception was reversed in male rats by atropine and unaffected by mecamylamine, whereas it was partially reduced by each antagonist alone in females and completely reversed after injection of both. RJR-2403 was more potent in females than in males, whereas there was no sex difference to bethanechol. Phentolamine partially reversed antinociception from RJR-2403 in females. Paw temperature increased more rapidly in females than in males for the same lamp intensity. Conclusions These data demonstrate a large sex difference in antinociception to intrathecal neostigmine that is primarily the result of a nicotinic component in females. Phentolamine reversal suggests that part of this nicotinic component may rely on spinal norepinephrine release. A better understanding of this sex difference could lead to development of novel pain therapy for women.

FACTORS INFLUENCING THE EXCRETION OF A FAT-MOBILIZING SUBSTANCE IN THE URINE OF RATS

1966 ◽  
Vol 44 (1) ◽  
pp. 95-101 ◽  
Author(s):  
J. R. Beaton ◽  
A. J. Szlavko ◽  
J. A. F. Stevenson
Keyword(s):  
Body Weight ◽  
Sex Difference ◽  
Specific Activity ◽  
Young Male ◽  
Total Activity ◽  
Female Rats ◽  
Male Rats ◽  
Diabetic Rat ◽  
Adult Rats ◽  
Factors Influencing

The effect of various factors on excretion of a lipid-mobilizing activity in FMS IA (anorexigenic) and in FMS IB (fat-mobilizing) by the fasting rat has been investigated. During fasting, the greatest excretion of such activity in FMS IA and FMS IB occurred in the first 24 hours and diminished thereafter up to 72 hours; and the specific activity of FMS IB was greatest in the first 24 hours whereas that of FMS IA was constant throughout. The hypothalamicobese rat excretes FMS IA and FMS IB in greater than normal amounts. The alloxan-diabetic rat excretes less total activity of FMS IA and IB than do control animals. Young male rats excrete greater amounts of FMS IB, but not of FMS IA, than do adult rats, the greatest excretion per 100 g body weight being observed at approximately 37 days of age. At 27 days of age (prepuberty), male rats excreted a greater total activity of FMS IB but not of FMS IA than did female rats. At 90 days of age (post-puberty), there was no apparent sex difference in the amount of total activity of FMS IB excreted per rat, but when expressed per 100 g body weight, females excreted more FMS IB than did males.

scholarly journals Male gender increases sensitivity to proteinuria induced by mild NOS inhibition in rats: role of sex hormones

2000 ◽  
Vol 279 (4) ◽  
pp. F664-F670 ◽  
Author(s):  
A. Marjan G. Verhagen ◽  
Diana M. A. Attia ◽  
Hein A. Koomans ◽  
Jaap A. Joles
Keyword(s):  
Nitric Oxide ◽  
Sex Hormones ◽  
Oxide System ◽  
Female Rats ◽  
Male Rats ◽  
Time Control ◽  
Ovx Rats ◽  
Increased Sensitivity ◽  
Dose Dependent Increase

Men are at greater risk for renal injury than women. We studied whether male rats are more sensitive to the hypertensive and proteinuric effects of chronic nitric oxide sythase (NOS) inhibition than female rats. In addition, we studied whether androgens or estrogens are responsible for differences in sensitivity to proteinuria induced by chronic NOS inhibition. Females and males were treated with 10, 20, 30, and 100 mg/l N ω-nitro-l-arginine (l-NNA) during 24 wk. Systolic blood pressure (SBP) and proteinuria were measured regularly and compared with time-control measurements in control females and males. In females and males treatment with 10 mg/l l-NNA had no effect on SBP or proteinuria. Treatment with 20, 30, and 100 mg/l l-NNA resulted in a dose-dependent increase in SBP that was similar in males and females. However, females treated with 20 and 30 mg/ll-NNA were resistant to the development of proteinuria: maximum values were 16 ± 7 and 46 ± 21, respectively, vs. 16 ± 3 mg/day in controls, whereas males treated with those doses showed an increase in proteinuria [139 ± 35 ( P< 0.05) and 318 ± 82 ( P < 0.01), respectively, vs. 55 ± 11 mg/day in controls]. Treatment with 100 mg/ll-NNA increased proteinuria similarly in both females and males. To study the role of sex hormones in differences in sensitivity to proteinuria induced by mild chronic NOS inhibition, treatment with 20 mg/l l-NNA was repeated in ovariectomized (Ovx) and orchidectomized rats. Ovariectomy did not affect the increase in SBP caused by 20 mg/l l-NNA, but, in contrast to intact females, this dose of l-NNA did cause Ovx rats to develop proteinuria (51 ± 16 vs. 16 ± 7 mg/day in control Ovx rats; P < 0.05). Orchidectomy completely prevented the increased SBP as well as proteinuria induced by 20 mg/ll-NNA in male rats. In conclusion, male rats are more sensitive than female rats to develop proteinuria induced by mild chronic NOS inhibition. Estrogens provide some protection in females, whereas androgens are responsible for the increased sensitivity of male rats to proteinuria induced by mild chronic NOS inhibition. Risk factors associated with a compromised nitric oxide system may be more detrimental to the kidney in men than in women.

scholarly journals GPER modulates tone and coronary vascular reactivity in male and female rats

2017 ◽  
Vol 59 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Angelina Rafaela Debortoli ◽  
Wender do Nascimento Rouver ◽  
Nathalie Tristão Banhos Delgado ◽  
Vinicius Mengal ◽  
Erick Roberto Gonçalves Claudio ◽  
...  
Keyword(s):  
Protein Expression ◽  
Vascular Reactivity ◽  
Coronary Circulation ◽  
Superoxide Production ◽  
Female Rats ◽  
Male Rats ◽  
Coronary Perfusion ◽  
Dependent Manner ◽  
Coronary Tone

Compared with age-matched men, premenopausal women are largely protected from coronary artery disease, a difference that is lost after menopause. The effects of oestrogens are mediated by the activation of nuclear receptors (ERα and ERβ) and by the G protein-coupled oestrogen receptor (GPER). This study aims to evaluate the potential role of GPER in coronary circulation in female and male rats. The baseline coronary perfusion pressure (CPP) and the concentration–response curve with a GPER agonist (G-1) were evaluated in isolated hearts before and after the blockade of GPER. GPER, superoxide dismutase (SOD-2), catalase and gp91phox protein expression were assessed by Western blotting. Superoxide production was evaluated ‘in situ’ via dihydroethidium fluorescence (DHE). GPER blockade significantly increased the CPP in both groups, demonstrating the modulation of coronary tone by GPER. G-1 causes relaxation of the coronary bed in a concentration-dependent manner and was significantly higher in female rats. No differences were detected in GPER, SOD-2 and catalase protein expression. However, gp91phox expression and DHE fluorescence were higher in male rats, indicating elevated superoxide production. Therefore, GPER plays an important role in modulating coronary tone and reactivity in female and male rats. The observed differences in vascular reactivity may be related to the higher superoxide production in male rats. These findings help to elucidate the role of GPER-modulating coronary circulation, providing new information to develop a potential therapeutic target for the treatment of coronary heart disease.

FAILURE OF DIHYDROTESTOSTERONE TO ELICIT SEXUAL BEHAVIOUR IN THE FEMALE CAT

1977 ◽  
Vol 75 (1) ◽  
pp. 173-174 ◽  
Author(s):  
VERONICA A. CERNY
Keyword(s):  
Sexual Behaviour ◽  
Female Rats ◽  
University Of Pennsylvania ◽  
Male Rat ◽  
Peripheral Target ◽  
Target Tissue ◽  
Male And Female ◽  
Behavioural Effects ◽  
Male And Female Rats ◽  
Target Organs

Laboratory of Anatomy, Department of Animal Biology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, U.S.A. (Received 28 March 1977) Testosterones have stimulatory effects on peripheral target tissue and sexual behaviour in male and female rats (Beach, 1942), guinea-pigs (Young, 1961; Diamond & Young, 1963), rabbits (Palka & Sawyer, 1966; Beyer & Rivaud, 1973) and cats (Green, Clemente & de Groot, 1957; Young, 1961; Whalen & Hardy, 1970). 5α-Androstan-17β-ol-3-one (dihydrotestosterone, DHT) has stimulatory effects on peripheral target organs, and like testosterones, a negative feedback effect on the pituitary gland and hypothalamus (Feder, 1971). No behavioural effects were seen in male or female rats when DHT was injected systemically (Beyer, Morali & Cruz, 1971; Feder, 1971) nor in the male rat when it was administered intracerebrally (Johnston & Davidson, 1972). Many experiments support the hypothesis that only androgens that can be aromatized to oestrogens can elicit sexual behaviour and

scholarly journals Two strategies used to solve a navigation task: A different use of the hippocampus by males and females? A preliminary study in rats

2018 ◽  
Vol 39 (2) ◽  
pp. 319-339 ◽  
Author(s):  
Ferran Lugo ◽  
Marta N. Torres ◽  
V.D. Chamizo
Keyword(s):  
Dorsal Hippocampus ◽  
Female Rats ◽  
Male Rats ◽  
Males And Females ◽  
Preliminary Study ◽  
Types Of Information ◽  
Landmark Learning ◽  
Source Of Information ◽  
Geometry Learning

AbstractThere is abundant research (both in rodents and in humans) showing that males and females often use different types of information in spatial navigation. Males prefer geometry as a source of information, whereas females tend to focus on landmarks (which are often near to a goal objects). However, when considering the role of the hippocampus, the research focuses primarily on males only. In the present study, based on Rodríguez, Torres, Mackintosh, and Chamizo’s (2010, Experiment 2) navigation protocol, we conducted two experiments, one with males and another with females, in order to tentatively evaluate the role of the dorsal hippocampus in the acquisition of two tasks: one based on landmark learning and the alternate one on local pool-geometry learning. Both when landmark learning and when geometry learning, Sham male rats learned significantly faster than Lesion male animals. This was not the case with female rats in geometry learning. These results suggest that the dorsal hippocampus could play an important role in males only.

scholarly journals Sex Difference in Plasma Deoxyribonuclease Activity in Rats

2021 ◽  
pp. 913-920
Author(s):  
Ľ Janovičová ◽  
B. Gromová ◽  
D. Drobná ◽  
B. Konečná ◽  
E. Renczés ◽  
...  
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Extracellular Dna ◽  
Female Rats ◽  
Male Rats ◽  
Dnase Activity ◽  
Adult Rats ◽  
Opposite Sex ◽  
Diffusion Assay ◽  
Deoxyribonuclease Activity

Extracellular DNA (ecDNA) activates immune cells and is involved in the pathogenesis of diseases associated with inflammation such as sepsis, rheumatoid arthritis or metabolic syndrome. DNA can be cleaved by deoxyribonucleases (DNases), some of which are secreted out of cells. The aim of this experiment was to describe plasma DNase activity in relation to extracellular DNA in adult rats, to analyse potential sex differences and to prove whether they are related to endogenous testosterone. Adult Lewis rats (n=28) of both sexes were included in the experiment. Male rats were gonadectomized or sham-operated and compared to intact female rats. Plasma ecDNA and DNase activity were measured using fluorometry and single radial enzyme diffusion assay, respectively. Concentrations of nuclear ecDNA and mitochondrial ecDNA were determined using real-time PCR. Females had 60% higher plasma DNase activity than males (p=0.03). Gonadectomy did not affect plasma DNase in males. Neither the concentration of total ecDNA, nor nuclear or mitochondrial DNA in plasma differed between the groups. No significant correlations between DNase and ecDNA were found. From previous studies on mice, it was expected, that male rats will have higher DNase activity. In contrast, our study in rats showed the opposite sex difference. This sex difference seems not to be caused by endogenous testosterone. Interestingly, no sex differences were observed in plasma ecDNA suggesting a complex or missing association between plasma ecDNA and DNase. The observed sex difference in plasma DNase should be taken into account in animal models of ecDNA-associated diseases.

Effects of steroid hormones on cyclic adenosine 3′,5′-monophosphate levels in the rat lung

1992 ◽  
Vol 134 (1) ◽  
pp. 73-76 ◽  
Author(s):  
B. M. Nabishah ◽  
B. A. K. Khalid ◽  
P. B. Morat ◽  
A. K. Alias ◽  
M. Zainuddin
Keyword(s):  
Steroid Hormones ◽  
Progesterone Receptors ◽  
Female Rats ◽  
Male Rats ◽  
Normal Female ◽  
Rat Lung ◽  
Camp Content ◽  
Rat Lungs ◽  
Camp Levels

ABSTRACT The possible role of cyclic adenosine 3′,5′-monophosphate (cAMP) in mediating the action of steroid hormones was investigated using the rat lung. Male rats were adrenalectomized and treated with olive oil, dexamethasone, corticosterone, deoxycorticosterone (DOC) or progesterone. At the end of 10 days, 100 μg isoprenaline/kg was injected intraperitoneally 5 min before the animals were killed to stimulate cAMP production. Adrenalectomy significantly decreased cAMP levels in the rat lung. Dexamethasone and corticosterone pretreatment reversed the effect of adrenalectomy whereas progesterone pretreatment but not DOC pretreatment significantly decreased lung cAMP levels. Cyclic AMP levels in normal female rats, whether pregnant or not, were not significantly different from those in male rats. We concluded that the absence of glucocorticoid, as after adrenalectomy, decreased the cAMP levels in rat lungs and that this could be reversed by either dexamethasone or corticosterone replacement. Progesterone reduced the cAMP content in rat lungs by acting as a glucocorticoid antagonist or by acting directly via progesterone receptors. Journal of Endocrinology (1992) 134, 73–76

Sign in / Sign up

Export Citation Format

Share Document