SPECIFIC SUPPRESSION OF FOLLICLE-STIMULATING HORMONE SECRETION IN GONADECTOMIZED MALE AND FEMALE RATS WITH INTRASPLENIC OVARIAN TRANSPLANTS

1978 ◽  
Vol 78 (3) ◽  
pp. 399-406 ◽  
Author(s):  
J. TH. J. UILENBROEK ◽  
R. TILLER ◽  
F. H. DE JONG ◽  
F. VELS
Keyword(s):  
Hormone Secretion ◽  
Serum Levels ◽  
Female Rats ◽  
Male Rats ◽  
Vaginal Smears ◽  
Intact Male ◽  
Male And Female ◽  
Kidney Capsule ◽  
Specific Suppression ◽  
Male And Female Rats

Adult male and female rats received an ovarian homotransplant under the kidney capsule or in the spleen 14 days after gonadectomy. After transplantation under the kidney capsule, the high levels of both LH and FSH normally observed after gonadectomy decreased to the levels found in intact male and female rats. After transplantation into the spleen, however, the serum levels of LH increased still further, although a decrease was observed in the level of FSH. In male rats, the concentrations of oestradiol-17β in the plasma increased from 17 to 56 pg/ml after transplantation of an ovary under the kidney capsule; the concentration was not increased after intrasplenic ovarian transplantation. In female rats with an intrasplenic transplant, the uterine weight did not increase and vaginal smears were not cornified. Administration of oestrogen and progesterone to produce approximately the concentrations found in rats with an intrasplenic transplant did not result in decreased concentrations of FSH. These results suggest that the ovary secretes a substance with specific FSH-suppressing activity, which is not inactivated by the liver.

Effects of the new prolactin-producing tumour 7315b on gonadotrophin secretion in adult male and female rats

1989 ◽  
Vol 120 (2) ◽  
pp. 261-268 ◽  
Author(s):  
A. Kooy ◽  
R. F. A. Weber ◽  
M. P. Ooms ◽  
J. T. M. Vreeburg
Keyword(s):  
Serum Levels ◽  
Female Rats ◽  
Male Rats ◽  
Suitable Model ◽  
Intact Male ◽  
Adult Rats ◽  
Male And Female ◽  
Male And Female Rats ◽  
Serum Lh ◽  
Gonadotrophin Secretion

ABSTRACT The effects of the transplantable purely prolactin-secreting tumour 7315b on serum gonadotrophins were studied in adult rats. Possible contributions of the adrenals to the tumour-induced inhibition of serum LH and FSH were evaluated. The suppressive actions of tumour 7315b on serum gonadotrophins in gonadectomized plus adrenalectomized male and female rats were compared. Within 4 weeks after inoculation of tumour 7315b in intact male rats very high levels of prolactin and decreased serum levels of gonadotrophins and testosterone were recorded. At autopsy reduced weights of testes and accessory sex organs and slightly increased adrenal weights were found. In addition, in animals treated with a small testosterone-filled capsule after castration, tumour 7315b reduced serum concentrations of LH and FSH. Adrenalectomy did not prevent this suppressive action of the tumour on the post-castration rise of serum gonadotrophins. Suppression of serum gonadotrophins during hyperprolactinaemia was greater in gonadectomized plus adrenalectomized female rats than in male rats, indicating that the degree of the tumour-induced suppression of LH and FSH after castration is determined to a large extent by the sex of the animal. The purely prolactin-secreting tumour 7315b has therefore been shown to be a suitable model for studying the effects of severe hyperprolactinaemia on the pituitary-gonadal axis in rats. Journal of Endocrinology (1989) 120, 261–268

scholarly journals Hydration with Mannitol and Dextrose May Promote Cisplatin-Induced Nephrotoxicity: Test of Five Protocols of Hydration during Cisplatin Therapy in Rat Models

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mohammad-Sedigh Khosravi ◽  
Alireza Samimiat ◽  
Bahar Mazaheri ◽  
Farzaneh Ashrafi ◽  
Ardeshir Talebi ◽  
...  
Keyword(s):  
Tumor Therapy ◽  
Kidney Tissue ◽  
Serum Levels ◽  
Female Rats ◽  
Male Rats ◽  
Male And Female ◽  
Male And Female Rats ◽  
Female Wistar Rats ◽  
Solid Tumor Therapy ◽  
Cisplatin Therapy

Backgrounds. Cisplatin (CP) still is a novel choice for solid tumor therapy, but it is accompanied with the side effect of nephrotoxicity. Hydration may reduce the risk of CP-induced nephrotoxicity, while the issue is still challenging. In this study, five types of hydration protocols including saline, mannitol, dextrose saline, saline plus furosemide, and saline plus mannitol were examined in both sexes of rats during CP therapy. Methods. Seventy-six male and female Wistar rats in 14 groups of experiments were subjected to CP therapy, and five types of hydration protocols were implemented, and the induced nephrotoxicity was evaluated via biochemical markers, kidney function parameters, and pathology investigation. Results. Male and female rats had different responses to hydration protocol types. The higher mortality rate was seen in female rats that received mannitol or dextrose hydration types. In addition, the serum levels of blood urea nitrogen (BUN) and creatinine (Cr) and sodium excretion fraction (ENa%) increased and the clearance of Cr (ClCr) decreased significantly ( P < 0.05 ) in female rats hydrated with saline plus furosemide or mannitol plus saline-treated groups. The worsened condition in male rats is observed in the mannitol hydration group with a significant decrease of ClCr and significant increase of serum BUN and Cr and ENa% ( P < 0.05 ). The higher kidney tissue damage score (KTDS) in the mentioned groups verified the findings. Conclusion. Hydration with mannitol or dextrose promotes the risk of nephrotoxicity during CP therapy with more intensity on the female.

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

INVOLVEMENT OF INHIBIN IN THE REGULATION OF FOLLICLE-STIMULATING HORMONE CONCENTRATIONS IN PREPUBERTAL AND ADULT, MALE AND FEMALE RATS

1980 ◽  
Vol 86 (1) ◽  
pp. 79-92 ◽  
Author(s):  
W. P. HERMANS ◽  
E. C. M. VAN LEEUWEN ◽  
M. H. M. DEBETS ◽  
F. H. DE JONG
Keyword(s):  
Follicle Stimulating Hormone ◽  
Female Rats ◽  
Male Rats ◽  
Intact Male ◽  
Adult Rats ◽  
Physiological Factor ◽  
Male And Female ◽  
Male And Female Rats ◽  
Pituitary Secretion ◽  
Fast Acting

Administration of steroid-free bovine follicular fluid (bFF), containing inhibin-like activity, depressed levels of FSH measured 4 h after injection in intact adult and 35-day-old female rats, but not in younger females. Suppression of FSH was also observed in intact male rats, aged 55 days, but not in older and younger male rats. Eight hours after injection of bFF, FSH levels were depressed in 15-day-old and older immature and adult rats of both sexes. Male and female rats, gonadectomized 2 days earlier, responded similarly to bFF treatment as did the intact animals. In a second experiment it was found that the rise of FSH levels, occurring within 8 h of gonadectomy, decreased with age in male and increased with age in female rats. Steroid treatment was found to prevent the rise in FSH levels partially in 15-day-old male and completely in 25-day-old female rats, whereas treatment with bFF was fully effective in blocking the FSH rise in both immature and adult rats of both sexes. It is concluded that inhibin might be a major physiological factor in a fast-acting control of FSH concentrations from at least the age of 25 days onwards in female rats. In male rats its physiological significance might be limited to the prepubertal period, despite the fact that pituitary secretion of FSH is suppressed by exogenous inhibin-like activity at all ages studied.

EFFECTS OF TESTOSTERONE ON PITUITARY CORTICOTROPHIN AND ADRENAL STEROID SECRETION IN MALE AND FEMALE RATS

1963 ◽  
Vol 43 (4) ◽  
pp. 601-608 ◽  
Author(s):  
Julian I. Kitay
Keyword(s):  
Plasma Corticosterone ◽  
Female Rats ◽  
Male Rats ◽  
Intact Male ◽  
Male And Female ◽  
Adrenal Steroid ◽  
Adrenal Steroidogenesis ◽  
Male And Female Rats

ABSTRACT Administration of a depot testosterone preparation to male and female rats resulted in no change in body or pituitary weight in either sex. Pituitary corticotrophin content was unaltered in male animals but was reduced in females. Adrenal weights and adrenal RNA and DNA contents were decreased in both sexes. Plasma corticosterone concentrations were unaffected in males but were reduced in female rats after stress or corticotrophin injection. Hepatic reduction of ring A in vitro and biological half-life of corticosterone in vivo were unchanged in male animals but impaired in females. Testosterone administration to intact male rats significantly increased adrenal steroidogenesis measured in vitro. A significant decrease in steroid production was found in intact females but increased steroidogenesis was observed in adrenals from testosterone-treated oophorectomized animals. No effect was obtained following addition of testosterone directly in vitro. The data suggest that testosterone leads both to diminution of corticotrophin secretion and enhancement of adrenal steroid secretory capacity. In intact female rats, these effects are complicated by suppression of oestrogen secretion, the effects of which have been reported previously.

Estrogen and prothrombin synthesis: effect of estrogen on absorption of vitamin K1

1977 ◽  
Vol 232 (1) ◽  
pp. H12-H17 ◽  
Author(s):  
D. W. Jolly ◽  
C. Craig ◽  
T. E. Nelson
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Thoracic Duct Lymph ◽  
Albino Rats ◽  
Vitamin K1 ◽  
Intact Male ◽  
Deficient Diet ◽  
Castrate Male ◽  
Male And Female ◽  
Male And Female Rats

Intact male and female albino rats fed a vitamin K-deficient diet develop a plasma prothrombin-proconvertin deficiency. Male rats respond with a precipitous drop to approximately 20–30% of normal plasma levels within 2–5 days, whereas female rats respond at a slower rate. Ethynylestradiol, 5–10 mug/day, or castration, reduces the progressive decline of plasma prothrombin-proconvertin seen in nonsupplemented intact male rats. The response of castrate females differs little from the response of intact females. Ethynylestradiol, 5–10 mug/day, affects both castrate males and females similarly, limiting the prothrombin-proconvertin decrease to about 13% below control value after 14 days. Intestinal absorption of vitamin K1 measured in the thoracic duct lymph of pentobarbital-anesthetized castrate male and female rats was shown to increase significantly after estrogen treatment. Estrogen-treated castrate male and female rats absorbed 25.8 mug and 11.8 mug vitamin K1, respectively. Nontreated control castrate male and female rats absorbed 0.0 mug and 1.2 mug, respectively, during a 240-min collection period. Use of radioactive vitamin K1 in similar experiments confirmed these results. Estrogen-treated castrate males absorbed vitamin K1 at the rate of 30-40 mug/g lymph whereas nontreated control males absorbed only about 6 mug/g lymph.

SEX DIFFERENCES IN THE CONCENTRATIONS OF GLUCOCORTICOID RECEPTORS IN RAT LIVER AND THYMUS

1979 ◽  
Vol 80 (1) ◽  
pp. 21-26 ◽  
Author(s):  
D. B. ENDRES ◽  
R. J. MILHOLLAND ◽  
F. ROSEN
Keyword(s):  
Sex Differences ◽  
Sex Difference ◽  
Glucocorticoid Receptors ◽  
Plasma Corticosterone ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Intact Male ◽  
Male And Female ◽  
Male And Female Rats

The effects in rats of adrenalectomy, hypophysectomy, ovariectomy or combinations of these operations on the concentrations of glucocorticoid receptors in the cytosol of liver and thymus were measured. The concentrations of glucocorticoid receptors were lower in cytosols from liver and thymus of female than of male rats. After adrenalectomy, there was a significant increase in the concentrations of receptors measured in the cytoplasm from the liver and thymus of female rats and from the liver of male rats. After adrenalectomy or hypophysectomy, there was no sex difference in the concentrations of glucocorticoid receptors in cytosols of liver or thymus. After ovariectomy, the concentration of receptors in cytosols from the thymus, but not from the liver, increased. Ovariectomized rats responded to adrenalectomy in the same way as intact male rats. The different responses shown by male and female rats to endocrine manipulation probably depend upon associated changes in plasma corticosterone concentrations which are influenced by the ovary. Differences in response between the liver and thymus probably reflect a preferential distribution of corticosterone to the liver rather than to the thymus.

scholarly journals Hyponatremia induced by vasopressin or desmopressin in female and male rats.

1993 ◽  
Vol 3 (9) ◽  
pp. 1600-1606
Author(s):  
J G Verbalis
Keyword(s):  
Water Content ◽  
Brain Edema ◽  
Hormone Secretion ◽  
Female Rats ◽  
Male Rats ◽  
Brain Water Content ◽  
Male And Female ◽  
Inappropriate Antidiuretic Hormone Secretion ◽  
Male And Female Rats ◽  
Brain Water

Previous studies have demonstrated that hyponatremia induced by continuous sc infusion of desmopressin (dDAVP) in combination with a liquid diet allows brain volume adaptation with negligible morbidity and mortality in rats. In contrast, some studies of hyponatremia induced by injections of long-acting preparations of arginine vasopressin (AVP) have reported mortality rates as high as 20 to 80%. To evaluate the possibility that the use of AVP to produce antidiuresis may cause greater mortality as a result of increased brain edema, this study examined brain water and electrolyte contents of male and female rats after varying periods of hyponatremia induced by continuous sc infusions of either dDAVP (5 ng/h) or AVP (100 ng/h). Rats infused with AVP had AVP levels in plasma elevated into ranges reported in patients with the syndrome of inappropriate antidiuretic hormone secretion (17.5 +/- 2.0 pg/mL); however, despite the production of comparably severe degrees of hyponatremia with both AVP and dDAVP infusions (105 to 115 mmol/L), no mortality occurred in any of the rats (N = 40 AVP infused and N = 40 dDAVP infused). AVP- and dDAVP-induced hyponatremia both caused transient brain edema in female and male rats, but brain water content returned to the levels of normonatremic controls after 5 days in the females and 10 days in the males. However, at no time during the 10-day study period did brain water content differ significantly between rats infused with AVP or dDAVP, either in females or males. Decreases in brain electrolytes were also equivalent in the AVP- and dDAVP-infused male and female rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth hormone regulates the rodent hepatic epidermal growth factor receptor at a pretranslational level

1989 ◽  
Vol 3 (2) ◽  
pp. 113-120 ◽  
Author(s):  
S. Johansson ◽  
B. Husman ◽  
G. Norstedt ◽  
G. Andersson
Keyword(s):  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Growth Factor Receptor ◽  
Female Rats ◽  
Male Rats ◽  
Intact Male ◽  
Male And Female ◽  
Male And Female Rats ◽  
Epidermal Growth

ABSTRACT Recent studies have implicated the involvement of pituitary factor(s) in the regulation of hepatic epidermal growth factor receptor (EGF-R) levels. In the present study the possible role of GH as a regulator of EGF-R has been examined by measuring hepatic EGF-R mRNA and EGF binding in intact and GH-deficient rats and mice before and after administration of GH. Using a human EGF-R probe, 10·5 and 6·0 kb transcripts were detected in mouse and rat liver by Northern gel analysis. EGF-R mRNA was quantified by solution hybridization, and EGF binding determined by incubation of 125I-labelled EGF with a low-density membrane fraction. Levels of hepatic EGF-R mRNA and binding of EGF in female rats were about two-thirds of those in male rats. GH-deficient (lit/lit) male and female mice had approximately 10 and 25% respectively of the levels of EGF-R mRNA and EGF binding of intact male and female mice. Furthermore, hypophysectomized rats exhibited a reduced level of EGF-R mRNA and EGF binding, corresponding to about 20% of the levels detected in intact male rats. When hypophysectomized male and female rats received recombinant human GH (hGH) either as intermittent injections or by continuous infusion using osmotic minipumps, the EGF-R mRNA and EGF binding levels increased to about half those of the intact male animals. No differences between intermittent or continuous administration of hGH on the induction of EGF-R mRNA or EGF binding could be seen. The correlation between mRNA and binding levels suggests regulation at a pretranslational level. There was a reduction of EGF-R mRNA to female levels when intact male rats were given hGH. An additional reduction of EGF binding levels was seen in both intact male and female rats exposed continuously to GH. This may indicate additional translational and/or post-translational regulatory mechanisms.

SERUM CONCENTRATIONS OF TESTOSTERONE, OESTROGENS, LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE IN MALE AND FEMALE RATS DURING THE CRITICAL PERIOD OF NEURAL SEXUAL DIFFERENTIATION

1979 ◽  
Vol 80 (1) ◽  
pp. 103-110 ◽  
Author(s):  
S. F. PANG ◽  
A. R. CAGGIULA ◽  
V. L. GAY ◽  
R. L. GOODMAN ◽  
C. S. F. PANG
Keyword(s):  
Post Partum ◽  
Serum Levels ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Serum Concentrations ◽  
Male And Female ◽  
Rat Pups ◽  
Male And Female Rats ◽  
Sampling Times

Untreated male and female rat pups were killed 1–5 days post partum and the serum concentrations of testosterone, oestrogens, LH and FSH were determined by radioimmunoassay. At all five sampling times, the serum concentrations of testosterone in male rats were about three times higher than those in female rats, but serum levels of oestrogens did not differ between the sexes. Serum concentrations of LH and FSH were lower in male than in female pups. In another study, rats were decapitated 1–10 days after birth and serum concentrations of testosterone were determined with a different radioimmunoassay. Again, at all four sampling times, the concentration of testosterone was significantly higher in the male than in the female pups.

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