scholarly journals New Insights into the Role of Androgens in Wolffian Duct Stabilization in Male and Female Rodents

Endocrinology ◽  
2009 ◽  
Vol 150 (5) ◽  
pp. 2472-2480 ◽  
Author(s):  
Michelle Welsh ◽  
Richard M. Sharpe ◽  
Marion Walker ◽  
Lee B. Smith ◽  
Philippa T. K. Saunders
Keyword(s):  
Epithelial Cell ◽  
Female Rats ◽  
Male Rats ◽  
Wolffian Duct ◽  
Sexually Dimorphic ◽  
Male And Female ◽  
Cell Height ◽  
Androgen Action ◽  
Butyl Phthalate

Androgen-mediated wolffian duct (WD) development is programmed between embryonic d 15.5 (e15.5) and 17.5 in male rats, and WD differentiation has been shown to be more susceptible to reduced androgen action than is its initial stabilization. We investigated regulation of these events by comparing fetal WD development at e15.5–postnatal d0 in male and female androgen receptor knockout mice, and in rats treated from e14.5 with flutamide (100 mg/kg/d) plus di-n(butyl) phthalate (500 mg/kg/d) to block both androgen action and production, testosterone propionate (20 mg/kg/d) to masculinize females, or vehicle control. In normal females, WD regression occurred by e15.5 in mice and e18.5 in rats, associated with a lack of epithelial cell proliferation and increased apoptosis, disintegration of the basement membrane, and reduced epithelial cell height. Exposure to testosterone masculinized female rats including stabilization and partial differentiation of WDs. Genetic or chemical ablation of androgen action in males prevented masculinization and induced WD regression via similar processes to those in normal females, except this occurred 2–3 d later than in females. These findings provide the first evidence that androgens may not be the only factor involved in determining WD fate. Other factors may promote survival of the WD in males or actively promote WD regression in females, suggesting sexually dimorphic differences in the preprogrammed setup of the WD.

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

scholarly journals Histological modifications of the rat prostate following transection of somatic and autonomic nerves

2010 ◽  
Vol 82 (2) ◽  
pp. 397-404 ◽  
Author(s):  
Rosaura Diaz ◽  
Luis I. Garcia ◽  
Jose Locia ◽  
Milagros Silva ◽  
Sara Rodriguez ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Androgen Receptors ◽  
Prostate Gland ◽  
Male Rats ◽  
Autonomic Nerves ◽  
Neural Pathways ◽  
Cell Height ◽  
Afferent Nerves ◽  
Rat Prostate

It is known that hormones influence significantly the prostate tissue. However, we reported that mating induces an increase in androgen receptors, revealing a neural influence on the gland. These data suggested that somatic afferents (scrotal and genitofemoral nerves) and autonomic efferents (pelvic and hypogastric nerves) could regulate the structure of the prostate. Here we assessed the role of these nerves in maintaining the histology of the gland. Hence, afferent or efferent nerves of male rats were transected. Then, the ventral and dorsolateral regions of the prostate were processed for histology. Results showed that afferent transection affects prostate histology. The alveoli area decreased and increased in the ventral and dorsolateral prostate, respectively. The epithelial cell height increased in both regions. Efferent denervation produced dramatic changes in the prostate gland. The tissue lost its configuration, and the epithelium became scattered and almost vanished. Thus, afferent nerves are responsible for spinal processes pertaining to the trophic control of the prostate, activating its autonomic innervation. Hence, our data imply that innervation seems to be synergic with hormones for the healthy maintenance of the prostate. Thus, it is suggested that some prostate pathologies could be due to the failure of the autonomic neural pathways regulating the gland.

scholarly journals Role of Age and Sex in Chronic Thyroiditis in Rats Fed 3'-Methyl-4-Dimethylaminoazobenzene

1976 ◽  
Vol 13 (4) ◽  
pp. 295-302 ◽  
Author(s):  
M. D. Reuber ◽  
E. L. Glover
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Deficient Diet ◽  
Chronic Thyroiditis ◽  
Male And Female ◽  
Low Protein ◽  
Males And Females ◽  
The Difference ◽  
Age And Sex

Inbred male and female Buffalo strain rats were started at 4, 8, 12, 24, or 52 weeks of age on 0.06% 3'-methyl-4-dimethylaminoazobenzene in a low-protein, choline-deficient diet. Eight-week-old males and females were the most susceptible to the development of chronic thyroiditis, but females were more susceptible than the males. Female rats of other ages developed a slightly higher incidence of thyroiditis than the male rats, the difference being most noticeable for rats 12 weeks old.

Sodium appetite in rats after prolonged dietary sodium deprivation: a sexually dimorphic phenomenon

1991 ◽  
Vol 260 (6) ◽  
pp. R1082-R1088 ◽  
Author(s):  
E. M. Stricker ◽  
E. Thiels ◽  
J. G. Verbalis
Keyword(s):  
Female Rats ◽  
Dietary Sodium ◽  
Male Rats ◽  
Sexually Dimorphic ◽  
Nacl Solution ◽  
Aldosterone Secretion ◽  
Intact Male ◽  
Male And Female ◽  
Deprivation Period ◽  
Sodium Appetite

Little sodium appetite is observed when rats are deprived of dietary sodium for several days, presumably because aldosterone secretion minimizes renal sodium losses. However, the present studies indicate that when sodium deprivation is extended to 8 days, a spontaneous sodium appetite results that far exceeds urinary sodium losses during the deprivation period; indeed, adult male rats drank as much 0.5 M NaCl solution as rats ever have been reported to drink rapidly. In contrast, female rats drank much less saline after 8 days of sodium deprivation. Because of this sexual dimorphism in sodium appetite, we also studied NaCl intake in gonadectomized rats after 8 days of sodium deprivation. Both male and female gonadectomized rats drank comparable amounts of saline as intact male rats, but they consumed much less when treated with physiological amounts of estrogen during the sodium-deprivation period. These results indicate that a robust appetite for NaCl can be produced in rats by prolonged sodium deprivation and that estrogen can blunt the induced sodium appetite.

Taste reactivity responses in rats: influence of sex and the estrous cycle

1998 ◽  
Vol 274 (3) ◽  
pp. R718-R724 ◽  
Author(s):  
Sharon N. D. A. Clarke ◽  
Klaus-Peter Ossenkopp
Keyword(s):  
Estrous Cycle ◽  
Gonadal Hormones ◽  
Female Rats ◽  
Male Rats ◽  
Taste Reactivity ◽  
Male And Female ◽  
Food Items ◽  
Reactivity Test ◽  
The Impact

Gonadal hormones (e.g., estradiol) may regulate feeding by producing a shift in the taste or palatability of food items. This study examined the impact of endogenous gonadal hormones on palatability by investigating sex differences in taste responsivity, as well as the effect of the estrous cycle on taste responsivity, in a rodent model. In the taste reactivity test, male and female Long-Evans rats received a brief (1 min) intraoral infusion of one of three tastants: sucrose (0.3 M), quinine (0.0003 M), and a sucrose-quinine mixture (0.3 M sucrose and 0.0003 M quinine). Statistical analyses indicated that female rats tested during diestrus or proestrus produced significantly more ingestive responses than did male rats and fewer aversive responses than did both male rats and female rats tested during estrus or metestrus ( P < 0.05). These results indicate a sex difference in taste responsivity in the rat that is modulated by the reproductive status of female rats. This finding implies a role of gonadal hormones in the regulation of taste responsivity in the rat.

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.

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.

Effect of gonadectomy on AgRP-induced weight gain in rats

2008 ◽  
Vol 295 (6) ◽  
pp. R1747-R1753 ◽  
Author(s):  
Sean Z. Goodin ◽  
Alicia R. Keichler ◽  
Marissa Smith ◽  
Donna Wendt ◽  
April D. Strader
Keyword(s):  
Weight Gain ◽  
Food Intake ◽  
Activity Level ◽  
Female Rats ◽  
Male Rats ◽  
Sexually Dimorphic ◽  
Cell Surface Molecule ◽  
Male And Female ◽  
Male And Female Rats ◽  
The Central Nervous System

Agouti-related peptide (AgRP), the endogenous antagonist to the melanocortin 3 and 4 receptors, elicits robust hyperphagia and weight gain in rodents when administered directly into the central nervous system. The relative influence of AgRP to cause weight gain in rodents partially depends on the activity level of the melanocortin agonist-producing proopiomelanocortin neurons. Both proopiomelanocortin and AgRP neurons within the arcuate nucleus receive energy storage information from circulating peripheral signals such as leptin and insulin. Another modulator of AgRP activity includes the cell surface molecule syndecan-3. Because leptin and insulin affect food intake in a sexually dimorphic way in rodents and syndecan-3-deficient mice regulate adiposity levels through distinct physiological mechanisms, we hypothesized that AgRP-induced weight gain would also be sexually dimorphic in rats. In the present study, the behavioral and physiological effects of centrally-administered AgRP in male and female were investigated. In male rats, AgRP (1 nmol) induced 5 days ( P < 0.0001) of significantly elevated feeding compared with vehicle-treated controls, while females displayed 3 days of hyperphagia ( P < 0.05). However, 1 wk after the injection, both male and female rats gained the same percent body weight (6%). Interestingly, female rats exhibited a greater reduction in energy expenditure (vo2) following AgRP compared with male rats ( P < 0.05). Removal of the gonads did not alter cumulative food intake in male or female rats but did attenuate the dramatic reduction in Vo2 exhibited by females. Both intact and gonadectomized rats demonstrated significantly increased respiratory quotient supporting the anabolic action of AgRP ( P < 0.01). These findings are novel in that they reveal sex-specific underlying physiology used to achieve weight gain following central AgRP in rats.

Resynchronization patterns for urinary rhythms in rats after light-dark shifts

1985 ◽  
Vol 249 (4) ◽  
pp. R402-R409 ◽  
Author(s):  
J. Poulis ◽  
F. Roelfsema ◽  
D. van der Heide ◽  
D. Smeenk
Keyword(s):  
Control Systems ◽  
Control Period ◽  
Light Period ◽  
Female Rats ◽  
Male Rats ◽  
Dark Cycle ◽  
Male And Female ◽  
Male And Female Rats ◽  
Circadian Pacemakers

Diurnal urinary rhythms during a fixed 12:12 light-dark cycle were studied in male and female rats. After a control period of 9 days the light-dark cycle was shifted either +6 or -6 h by delaying or advancing the light period, respectively. Subsequently the resynchronization process was studied for 19–21 days. In both male and female rats an asymmetry effect was present: resynchronization was more rapid after a -6-h shift than after a +6-h shift. However, female rats exhibited a rate of resynchronization slower than male rats. During the process of resynchronization a state of transient internal dissociation was found for all urinary constituents. These results probably point to different control systems rather than to different circadian pacemakers. Further analysis of the role of sex steroid hormones is required in view of the sex variations reported.

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.

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