THE ROLE OF THE TESTIS IN THE RELEASE OF GONADOTROPHINS FROM THE HYPOPHYSIS

1962 ◽  
Vol 40 (2) ◽  
pp. 175-187 ◽  
Author(s):  
A. M. Taira ◽  
A. A. Tarkhan
Keyword(s):  
Leydig Cells ◽  
Interstitial Cells ◽  
Female Rats ◽  
List Type ◽  
Adult Rats ◽  
Male And Female Rats ◽  
Short Period ◽  
The One ◽  
Spermatogenic Epithelium

ABSTRACT To study the role of the spermatogenic epithelium and of the interstitial cells of Leydig in the release of the pituitary gonadotrophins, groups of normal, cryptorchid and castrated adult rats were joined parabiotically to immature male and female rats for a period of seven days. On examination of the genital organs of different recipients, it has been concluded that: In normal rats, there is no appreciable release of any gonadotrophin during the short period of parabiosis. The spermatogenic epithelium inhibits the release of FSH, while the interstitial cells liberate a hormone that inhibits the release of ICSH. Release of the gonadotrophin which causes luteinisation of the granulosa cells is not activated by cryptorchidism or castration. This gonadotrophin is different from the one responsible for stimulation of growth and functional activity of the Leydig cells. The term »LH« is better confined to the former and »ICSH« to the latter gonadotrophin. ICSH not only acts on the testis but also on the ovary and indirectly on the uterus; this action has been discussed.

INDUCTION OF GOITRE BY PTU OR KClO4 IN MALE AND FEMALE RATS. EFFECT OF GONADECTOMY

1973 ◽  
Vol 74 (1) ◽  
pp. 88-104 ◽  
Author(s):  
T. Jolín ◽  
M. J. Tarin ◽  
M. D. Garcia
Keyword(s):  
Iodine Content ◽  
High Plasma ◽  
Disc Electrophoresis ◽  
Female Rats ◽  
Male Rats ◽  
Adult Rats ◽  
Male And Female ◽  
Glucose Levels ◽  
Male And Female Rats ◽  
Tsh Levels

ABSTRACT Male and female rats of varying ages were placad on a low iodine diet (LID) plus KClO4 or 6-propyl-2-thiouracil (PTU) or on the same diet supplemented with I (control rats). Goitrogenesis was also induced with LID plus PTU in gonadectomized animals of both sexes. The weight of the control and goitrogen treated animals, and the weight and iodine content of their thyroids were determined, as well as the plasma PBI, TSH, insulin and glucose levels. The pituitary GH-like protein content was assessed by disc electrophoresis on polyacrylamide gels. If goitrogenesis was induced in young rats of both sexes starting with rats of the same age, body weight (B.W.) and pituitary growth hormone (GH) content, it was found that both the males and females developed goitres of the same size. On the contrary, when goitrogenesis was induced in adult animals, it was found that male rats, that had larger B.W. and pituitary GH content than age-paired females, developed larger goitres. However, both male and female rats were in a hypothyroid condition of comparable degree as judged by the thyroidal iodine content and the plasma PBI and TSH levels. When all the data on the PTU or KClO4-treated male and female rats of varying age and B.W. were considered together, it was observed that the weights of the thyroids increased proportionally to B.W. However, a difference in the slope of the regression of the thyroid weight over B.W. was found between male and female rats, due to the fact that adult male rats develop larger goitres than female animals. In addition, in the male rats treated with PTU, gonadectomy decreased the B.W., pituitary content of GH-like protein and, concomitantly, the size of the goitre decreased; an opposite effect was induced by ovariectomy on the female animals. However, when goitrogenesis was induced in weight-paired adult rats of both sexes, the male animals still developed larger goitres than the females. Among all the parameters studied here, the only ones which appeared to bear a consistent relationship with the size of the goitres in rats of different sexes, treated with a given goitrogen, were the rate of body growth and the amount of a pituitary GH-like protein found before the onset of the goitrogen treatment. Moreover, though the pituitary content of the GH-like protein decreased as a consequence of goitrogen treatment, it was still somewhat higher in male that in female animals. The present results suggest that GH may somehow be involved in the mechanism by which male and female rats on goitrogens develop goitres of different sizes, despite equally high plasma TSH levels.

scholarly journals Role of the oxytocin system in amygdala subregions in the regulation of social interest in male and female rats

Neuroscience ◽  
2016 ◽  
Vol 330 ◽  
pp. 138-149 ◽  
Author(s):  
Kelly M. Dumais ◽  
Andrea G. Alonso ◽  
Remco Bredewold ◽  
Alexa H. Veenema
Keyword(s):  
Social Interest ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats

Mesenteric vascular responses to vasopressin during development of DOCA-salt hypertension in male and female rats

1995 ◽  
Vol 268 (1) ◽  
pp. R40-R49 ◽  
Author(s):  
J. N. Stallone
Keyword(s):  
Sex Differences ◽  
Acute Treatment ◽  
Vascular Reactivity ◽  
Chronic Treatment ◽  
Female Rats ◽  
Salt Treatment ◽  
Male And Female Rats ◽  
Salt Hypertension ◽  
Vascular Responsiveness

Deoxycorticosterone acetate (DOCA)-salt hypertension develops to a greater extent in male (M) than in female (F) rats. To determine the role of the vasculature, reactivity to arginine vasopressin (AVP) and prostanoid output were examined in the isolated perfused mesenteric vasculature of hypertensive (HT) and normotensive-control (NTC) M and F rats after acute (1-wk) and chronic (4-wk) DOCA-salt treatment. Systolic blood pressure was significantly higher in M than in F HT rats (187 +/- 3 vs. 151 +/- 3 mmHg after 4 wk; P < 0.02). After acute treatment, vascular reactivity to AVP (maximal perfusion pressure) in HT was elevated in M (181 +/- 18 mmHg; P < 0.02) but not in F (135 +/- 6 mmHg) compared with NTC (90 +/- 6 mmHg, M vs. 119 +/- 5 mmHg, F). After chronic treatment, vascular reactivity to AVP in HT was elevated in both sexes (P < 0.02), although more in F (175 +/- 13 mmHg) than in M (141 +/- 11 mmHg). In contrast, vascular responsiveness to phenylephrine did not differ significantly between M and F NTC or HT preparations after either acute or chronic treatment. Sex differences in basal and AVP-induced 6-ketoprostaglandin (6-keto-PG) F1 alpha and PGE2 output by HT and NTC vasculature were reciprocal to sex differences in the vasoconstriction responses to AVP. After acute treatment, AVP-stimulated 6-keto-PGF1 alpha output by HT was elevated slightly in F (33.6 +/- 1.7 ng/3 min; P < or = 0.02) but not in M (49.9 +/- 4.3 ng/3 min) compared with NTC (23.5 +/- 2.6 ng/3 min, F vs. 34.7 +/- 4.9 ng/3 min, M). After chronic treatment, output by HT was enhanced in both sexes (P < or = to 0.02), although more in M (109 +/- 15.4 ng/3 min) than in F (68 +/- 6.6 ng/3 min)> These findings suggest that sex differences in the relative balance between AVP-induced vasoconstriction and vasodilatory prostanoid release may contribute to male-female differences in mesenteric vascular reactivity to AVP in NT and that disturbances in this balance may be responsible, at least in part, for the sex- and time-dependent changes in reactivity to AVP observed during the development of DOCA-salt hypertension.

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.

scholarly journals Effect of GABA-T on Reproductive Function in Female Rats

Animals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 567
Author(s):  
Wenyu Si ◽  
Hailing Li ◽  
Tiezhu Kang ◽  
Jing Ye ◽  
Zhiqiu Yao ◽  
...  
Keyword(s):  
Mrna Level ◽  
Reproductive Function ◽  
Female Rats ◽  
Enzyme Linked Immunosorbent Assay ◽  
Mrna Levels ◽  
Lactation Performance ◽  
Irreversible Inhibitor ◽  
Adult Rats ◽  
Expression Of Genes

This study explored the role of γ-aminobutyric acid transaminase (GABA-T) in the puberty and reproductive performance of female rats. Immunofluorescence technique, quantitative real-time PCR (RT-qPCR) and enzyme-linked immunosorbent assay (ELISA) were used to detect the distribution of GABA-T and the expression of genes and hormones in female rats, respectively. The results showed that GABA-T was mainly distributed in the arcuate nucleus (ARC), paraventricular nucleus (PVN) and periventricular nucleus (PeN) of the hypothalamus, and in the adenohypophysis, ovarian granulosa cells and oocytes. Abat mRNA level at 28 d was lowest in the hypothalamus and the pituitary; at puberty, it was lowest in the ovary. Abat mRNA level was highest in adults in the hypothalamus; at infancy and puberty, it was highest in the pituitary; and at 21 d it was highest in the ovary. After vigabatrin (GABA-T irreversible inhibitor) was added to hypothalamus cells, the levels of Abat mRNA and Rfrp-3 mRNA were significantly reduced, but Gnrh mRNA increased at the dose of 25 and 50 μg/mL; Kiss1 mRNA was significantly increased but Gabbr1 mRNA was reduced at the 50 μg/mL dose. In prepubertal rats injected with vigabatrin, puberty onset was delayed. Abat mRNA, Kiss1 mRNA and Gnrh mRNA levels were significantly reduced, but Rfrp-3 mRNA level increased in the hypothalamus. Vigabatrin reduced the concentrations of GABA-T, luteinizing hormone (LH) and progesterone (P4), and the ovarian index. Lactation performance was reduced in adult rats with vigabatrin treatment. Four hours after vigabatrin injection, the concentrations of GABA-T and LH were significantly reduced in adult and 25 d rats, but follicle-stimulating hormone (FSH) increased in 25 d rats. In conclusion, GABA-T affects the reproductive function of female rats by regulating the levels of Gnrh, Kiss1 and Rfrp-3 in the hypothalamus as well as the concentrations of LH and P4.

PHARMACOLOGICAL PROPERTIES OF NANDROLONE DECANOATE

1960 ◽  
Vol XXXV (III) ◽  
pp. 405-412 ◽  
Author(s):  
J. de Visser ◽  
G. A. Overbeek
Keyword(s):  
Levator Ani ◽  
Female Rats ◽  
High Dose ◽  
Levator Ani Muscle ◽  
List Type ◽  
Pharmacological Properties ◽  
Nandrolone Decanoate ◽  
Anabolic Activity ◽  
Male And Female Rats ◽  
Dose Levels

ABSTRACT 1. The pharmacological properties of nandrolone decanoate (= caprinate), by abbreviation nor-A. D., have been studied. 2. Nor-A. D. has a marked, long-lasting effect on the levator ani muscle of the castrated rat, but it has little activity on the seminal vesicles and prostate. 3. Nor-A. D. displays only weak gonad inhibiting properties in male and female rats. 4. The anti-oestrogenic activity is low. 5. At high dose levels the anabolic activity becomes maximal and the other effects become evident. The same can be expected to occur if injections are administered with too great a frequency. 6. Chronic toxicity studies in rats and dogs demonstrate its lack of toxicity.

Increased plasma osmolality stimulates peripheral and central vasopressin release in male and female rats

1994 ◽  
Vol 267 (4) ◽  
pp. R923-R928 ◽  
Author(s):  
M. Ota ◽  
J. T. Crofton ◽  
H. Liu ◽  
G. Festavan ◽  
L. Share
Keyword(s):  
Interstitial Fluid ◽  
Plasma Osmolality ◽  
Female Rats ◽  
Microdialysis Probe ◽  
Vasopressin Release ◽  
Arterial Blood ◽  
Plasma Vasopressin ◽  
Male And Female Rats ◽  
Supraoptic Nuclei

It has been demonstrated that the neurohypophysial hormones can be released intrahypothalamically by the paraventricular (PVN) and supraoptic nuclei. The present experiments were undertaken to determine whether a physiological stimulus for vasopressin release, increased plasma osmolality, will stimulate the release of vasopressin by the PVN into the surrounding interstitial fluid, and whether the responses are affected by gender. Intravenous infusion of 2.5 M NaCl for 60 min (0.1 ml.kg-1.min-1) in conscious rats resulted in an increased vasopressin concentration in the dialysate from a microdialysis probe adjacent to the PVN. This response was greater in nonestrous females than in males. On the other hand, the rise in the plasma vasopressin concentration was greater in males than in nonestrous females. Mean arterial blood pressure increased and heart rate decreased, but these responses were not affected by gender. The role of centrally released vasopressin in the control of the peripheral release of vasopressin is conjectural, but both responses may be modulated by the gonadal steroid hormones.

scholarly journals Influence of sex, estrous cycle, and estrogen on intracranial dural mast cells

Cephalalgia ◽  
2012 ◽  
Vol 32 (12) ◽  
pp. 924-931 ◽  
Author(s):  
Tanner Boes ◽  
Dan Levy
Keyword(s):  
Mast Cells ◽  
Estrous Cycle ◽  
Potential Role ◽  
Ovarian Hormones ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Migraine Headaches ◽  
Male And Female Rats ◽  
Quantitative Analyses

Background: The frequency of migraine headaches is higher in women than in men and in susceptible women attacks are related to changes in ovarian hormone levels. Intracranial mast cells (MCs) are likely to have a role in migraine headache genesis, and changes in the dural MC population might influence headache susceptibility. The present study thus tested the hypothesis that sex and ovarian hormones influence the density and phenotypic makeup of dural MCs. Methods: Histochemistry combined with quantitative analyses was used to investigate sex differences, estrous cycle and ovarian hormones on dural MC density, phenotype and degranulation level in male and female rats. Results: Our data show that in female rats, dural MC density fluctuates during the estrous cycle and is overall higher than in males. In ovariectomized rats, estradiol, but not progesterone, promoted an increase in dural MC density. This effect was abolished by a splenectomy, suggesting estrogen-related recruitment of MCs from the spleen. Finally, our data suggest that the phenotypic make up of dural MCs, which represents the level of cellular maturity, is also governed by changes in estrogen levels. Conclusions: Given the potential role of dural MCs in triggering headache, our data suggest that estrogen-related modulation of dural MC density and phenotypic makeup could have a role in mediating the higher frequency and severity of headaches such as migraine, in women.

Insulin-like growth factor-I mRNA expression in the interstitial cells of the rat testis

1993 ◽  
Vol 11 (3) ◽  
pp. 319-324 ◽  
Author(s):  
A Moore ◽  
C-L C Chen ◽  
J R E Davis ◽  
I D Morris
Keyword(s):  
Leydig Cell ◽  
Leydig Cells ◽  
Interstitial Cell ◽  
Buoyant Density ◽  
Testicular Tissue ◽  
Interstitial Cells ◽  
Adult Rats ◽  
Chain Cleavage ◽  
Igf I ◽  
Cell Fractions

ABSTRACT IGF-I mRNA has been demonstrated in testicular tissue and, more recently, localized specifically to Leydig cells. This study investigated the expression of IGF-I and side-chain cleavage enzyme (SCC) mRNA in two preparations of rat interstitial testicular cells which were separated by buoyant density into Leydig cell-enriched and -depleted fractions. RNA was prepared from interstitial cells obtained from the testes of untreated adult and immature rats and adult rats treated with human chorionic gonadotrophin (hCG) or ethane dimethanesulphonate (EDS; to destroy Leydig cells). IGF-I mRNA was detected in all samples, with five major transcripts ranging from 7·5 to 0·6 kb. Leydig cells (3β-hydroxysteroid dehydrogenase-positive and sensitive to EDS) expressed abundant IGF-I and SCC mRNAs, and levels of both were increased following hCG treatment. However, in addition, IGF-I mRNA which was derived from non-Leydig interstitial cells was detected, in the complete absence of SCC message, either in the more buoyant interstitial cells or in both interstitial cell fractions following the destruction of Leydig cells by EDS treatment. IGF-I expression in the Leydig cell-depleted cell fraction was also increased by hCG treatment, and it is therefore suggested that at least part of this non-Leydig interstitial cell IGF-I mRNA originates in Leydig cell precursors. In conclusion, Leydig cells are not the sole origin of IGF-I mRNA in the testis, and the non-Leydig cell expression may be an important component of testicular IGF-I production.

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