SEX DIFFERENCE IN THE INDUCTION OF LACTOGENIC RECEPTORS IN RAT LIVERS

1979 ◽  
Vol 92 (3) ◽  
pp. 532-541 ◽  
Author(s):  
Nobuaki Furuhashi ◽  
Victor S. Fang
Keyword(s):  
Binding Sites ◽  
Specific Binding ◽  
Elevated Serum ◽  
Serum Testosterone ◽  
Serum Levels ◽  
Significant Negative Correlation ◽  
Female Rats ◽  
Male Rats ◽  
Affinity Constant ◽  
Male And Female Rats

ABSTRACT The relationship between serum levels of growth hormone (rGH), prolactin (rPRL), lutenizing hormone (rLH), follicle-stimulating hormone (rFSH), corticosterone, oestrogen, (oestradiol-17β) and testosterone and the hepatic binding sites specific to [125I]human-prolactin (h-PRL) were investigated in normal rats, in rats bearing the GH- and PRL-secreting tumour (GH3), and in rats 14 days after tumour removal. The presence of GH3 tumour elevated serum levels of rGH and rPRL and concomitantly increased the hepatic binding of [125I] h-PRL; the male rats had a greater increase than the female rats. The increased binding was due to an increase in the specific membrane binding sites, whereas the affinity constant (Ka) was not changed. In both male and female rats, there was a significant positive correlation between serum rGH levels (P < 0.001) or serum rPRL (P < 0.02) and specific binding of [1251] h-PRL in female rats only (P < 0.02). In male rats, there was a significant negative correlation between serum testosterone levels and specific bindings of [125I]h-PRL (P < 0.05). These results suggest that rGH and rPRL regulates the hepatic h-PRL receptors in female rats, and testosterone predominantly inhibits the induction of the hepatic lactogenic receptors in male rats.

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.

Cytoplasmic estrogen, but not progestin, binding sites in male rat adipose tissues

1980 ◽  
Vol 239 (4) ◽  
pp. E237-E237
Keyword(s):  
Binding Sites ◽  
Specific Binding ◽  
Estradiol Benzoate ◽  
Female Rats ◽  
Male Rats ◽  
Male Rat ◽  
Adipose Tissues ◽  
Body Fat Content ◽  
Estrogen Binding ◽  
Fat Pads

Male rat adipose tissues contain cytoplasmic estrogen binding sites comparable to those found in females. This bindng is of high affinity (Kd = 1.7 x 10(-10) M) and is estrogen specific. Binding of 17 beta-estradiol was inhibited by radioinert estrogens (17 beta-estradiol and R 2858) but not by other steroids (progesterone, 5 alpha-dihydrotestosterone, and corticosterone). Estrogen binding sites were found in all fat pads studied, but levels were highest in the epididymal pads. Treatment of female rats with 17 beta-estradiol benzoate (E2B) induced cytoplasmic progestin receptors in adipose tissues, but in three separate experiments, E2B treatment (20 microgram/day for 3 days) failed to induce measurable progestin ([3H]R 5020) binding sites in males. E2B treatment reduced lipoprotein lipase (LPL) activity by approximately 75% in epididymal (male) and parametrial (female) fat pads. Concurrent progesterone treatment increased parametrial LPL activity in E2B-treated females, but progesterone had no effect on epididymal fat pad LPL activity in males. These findings are consistent with the hypothesis that in male rats aromatized (estrogenic) metabolites of testosterone may reduce body fat content and alter lipid metabolism by direct actions on adipose tissues.

Effects of corticotropin-releasing factor on energy balance in rats are sex dependent

1989 ◽  
Vol 257 (6) ◽  
pp. R1417-R1422 ◽  
Author(s):  
S. Rivest ◽  
Y. Deshaies ◽  
D. Richard
Keyword(s):  
Body Weight ◽  
Energy Balance ◽  
Food Intake ◽  
Serum Testosterone ◽  
Corticotropin Releasing Factor ◽  
Female Rats ◽  
Male Rats ◽  
Male And Female ◽  
Male And Female Rats ◽  
Significant Difference

The purpose of this study was to investigate the effects of a chronic intracerebroventricular administration of corticotropin-releasing factor (CRF) on energy balance of male and female rats. One week after their delivery to the laboratory, both male and female rats were divided into two groups. One group in each sex was treated with human/rat CRF, while another group was infused with the vehicle. Chronic administration of CRF was accomplished by means of miniosmotic pumps connected to a cannula that was stereotaxically directed into the third ventricle. Food intake and body weight were measured each day during the study. After 14 days of treatment, the rats were killed by decapitation. Energy, fat, and protein contents of the carcasses were quantified. Serum testosterone and estradiol were assayed in males and females, respectively. Administration of CRF significantly reduced body weight gain and food intake in male rats. No significant difference in those variables was observed between female rats treated with CRF and their controls infused with saline. Similarly, metabolizable energy intake and body energy gain were reduced in male rats infused with CRF, whereas no difference was observed between female animals treated with CRF and those infused with saline. In male rats, body fat and body protein contents were lower in CRF-treated than in saline-infused rats. In female rats, CRF did not affect body composition. Serum testosterone in male rats and serum estradiol in female animals were reduced after chronic infusion of CRF.(ABSTRACT TRUNCATED AT 250 WORDS)

Potential adverse effects of oseltamivir in rats: males are more vulnerable than females

2011 ◽  
Vol 89 (9) ◽  
pp. 623-630 ◽  
Author(s):  
Wael M. El-Sayed ◽  
Mohamed Ali Al-Kahtani
Keyword(s):  
Adverse Effects ◽  
Protein Profile ◽  
Antiviral Drug ◽  
Thioredoxin Reductase ◽  
Serum Levels ◽  
Female Rats ◽  
Male Rats ◽  
Glutathione S Transferase ◽  
Quinone Oxidoreductase ◽  
Male And Female Rats

Oseltamivir is the most widely used antiviral drug for the treatment and prophylaxis of influenza. However, not much is known about its adverse effects. The potential side effects were investigated in male and female rats (140–170 g). Oseltamivir was administered at 2.2 mg·kg–1·day–1 for 5 days. For both genders, treatment with oseltamivir resulted in significant reductions in the hepatic activities of glutathione reductase, glutathione peroxidase, and glutathione S-transferase. Also for both genders, oseltamivir produced modest reductions in the hepatic activities of UDP-glucuronosyltransferase, quinone oxidoreductase, thioredoxin reductase, CYP1A1/2, and CYP3A, as well as hepatic glutathione content. For both genders, neither the kidney functions nor protein profile was affected by oseltamivir. Oseltamivir also caused significant elevation in serum levels of both triacylglycerols and LDL-cholesterol and in the activity of γ-glutamyl transpeptidase, in both genders. For male animals only, oseltamivir treatment elevated the serum level of total cholesterol as well as the activity of serum alanine aminotransferase, and reduced the hepatic activities of superoxide dismutase and catalase. Oseltamivir caused oxidative stress and acute toxicity in the liver, and disrupted the cholesterol and lipid metabolism but was less likely to cause serious drug interactions. There was a sexual differentiation in these adverse effects, with adverse effects being more evident in male rats.

Evaluation of thyroid function in neonatal and adult rats: The neglected endocrine mode of action

2003 ◽  
Vol 75 (11-12) ◽  
pp. 2055-2068 ◽  
Author(s):  
M. S. Christian ◽  
N. A. Trenton
Keyword(s):  
Metabolic Rate ◽  
Thyroid Function ◽  
Critical Period ◽  
Serum Levels ◽  
Thyroid Stimulating Hormone ◽  
Female Rats ◽  
Male Rats ◽  
Adult Rats ◽  
Male And Female Rats ◽  
Serum Tsh

Although known to regulate growth and development, cellular metabolism, the use of oxygen, and basal metabolic rate, thyroid hormones have been only minimally evaluated in neonatal rodents at critical times of development. Despite some modulation of metabolic rate by other hormones, such as testosterone, growth hormone, and norepinephrine, 3,5,3'-triiodothyronine (T3) and 3,5,3',5'-tetraiodothyronine (T4) are the most important metabolic rate modulators. Endpoints used for thyroid function assessment in neonatal and adult rats include thyroid-stimulating hormone (TSH), T3, and T4 levels and histopathology. In rodents, decreased serum levels of T3 and T4 and increased serum TSH levels, with sustained release of TSH and resultant follicular cell hypertrophy/hyperplasia, are typical hormonal and histopathological findings attributable to compounds altering thyroid function. Hypothyroidism early in the neonatal period can affect reproductive endpoints in both male and female rats, with the critical period of exposure being the first two weeks postnatal. Hypothyroidism has been shown to reduce gonadotrophin levels and delay pubertal spermatogenesis in male rats and to block gonadotropin-induced first ovulation in immature female rats by decreasing FSH and luteinizing hormone (LH) serum concentrations. Inclusion of evaluations of TSH, T3, and T4 assays in multigeneration and developmental neurotoxicity protocols may assist in risk assessments.

EFFECTS OF ENDOCRINE MANIPULATIONS ON OESTROGEN BINDING IN CYTOSOLS FROM RAT SKELETAL AND PERINEAL MUSCLES

1980 ◽  
Vol 85 (3) ◽  
pp. 351-358 ◽  
Author(s):  
F. T. DIONNE ◽  
J. Y. DUBÉ ◽  
G. FRENETTE ◽  
R. R. TREMBLAY
Keyword(s):  
Binding Sites ◽  
Hormonal Regulation ◽  
Binding Capacity ◽  
Levator Ani ◽  
Gonadal Hormones ◽  
Female Rats ◽  
Male Rats ◽  
Thigh Muscles ◽  
Male And Female Rats ◽  
Intact Rats

Hormonal regulation of cytosolic oestradiol-binding sites in the levator ani bulbocavernosus (LA/BC) muscles of male rats and in thigh muscles from male and female rats was investigated. Twenty-four hours after gonadectomy and/or adrenalectomy, the number of unoccupied oestradiol-binding sites was significantly increased in cytosols prepared from LA/BC muscles while these treatments had no effect on thigh muscles from male rats. Only a combination of both treatments led to a significant increase of oestradiol-binding sites in cytosols prepared from the thigh muscles of female rats when compared with those of intact rats at dioestrus. The number of oestradiol-binding sites in the thigh muscles of female rats was found to vary during the oestrous cycle with values significantly lower at pro-oestrus than at dioestrus. The increase in oestradiol-binding sites observed in cytosols prepared from muscles of adrenalectomized or gonadectomized plus adrenalectomized rats was prevented by an injection of corticosterone (3 mg, s.c.) at the time of surgery. Twenty-one days after gonad and/or adrenal ablation, the mean concentration of oestradiol-binding sites in the three tissues under study was higher than in these tissues from intact rats, and in some groups the levels of oestradiol-binding sites were significantly higher than they had been 24 h after the same surgical treatments. Muscles from male rats hypophysectomized for 28 days possessed levels of oestradiol-binding sites equivalent to male rats deprived of steroid hormones for 21 days. Dexamethasone treatment of male rats (100 μg/day for 14 days) led to a progressive decrease of oestradiol-binding sites of LA/BC and thigh muscles. This study has shown that adrenal and gonadal hormones exert both short- and long-acting repressive effects on the oestradiol-binding capacity of rat muscles.

EFFECT OF MESENCEPHALIC STIMULATION ON THE RELEASE OF GONADOTROPHINS

1970 ◽  
Vol 48 (4) ◽  
pp. 527-539 ◽  
Author(s):  
H. F. CARRER ◽  
S. TALEISNIK
Keyword(s):  
Follicle Stimulating Hormone ◽  
Elevated Serum ◽  
Serum Levels ◽  
Female Rats ◽  
Continuous Illumination ◽  
Electrolytic Deposition ◽  
Inhibitory Effects ◽  
Male And Female Rats ◽  
Serum Lh ◽  
Stimulation Of

SUMMARY Different regions of the midbrain were stimulated by electrolytic deposition of iron from stainless steel unipolar electrodes. Electrochemical stimulation of the ventral tegmental area (VTA), the raphe nuclei or the peri-aqueductal grey in rats in pro-oestrus was effective in preventing spontaneous ovulation. No blockade of ovulation was observed by stimulating other mesencephalic structures. After stimulation in the VTA there was a significant decrease of the elevated serum levels of luteinizing hormone (LH) found after an injection of progesterone into pro-oestrous rats or into ovariectomized—oestrogen-primed animals. In contrast, electrochemical stimulation of the dorsal mesencephalic tegmentum, lateral and inferior to the peri-aqueductal grey, in rats in which spontaneous ovulation had been blocked by continuous illumination, resulted in an ovulatory response. Serum LH was found to increase in gonadectomized—oestrogen-treated male and female rats after stimulating this area. No significant changes in serum follicle-stimulating hormone were found after stimulation in the ventral or dorsal tegmentum. It is concluded that both stimulatory and inhibitory influences on the release of gonadotrophin can be evoked by stimulating mesencephalic structures. The stimulatory and inhibitory effects could depend on the activation of noradrenergic and serotoninergic systems, respectively.

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.

Observations on the effects of prolactin on LH-receptors and steroidogenesis in corpus luteum and testis of the hypophysectomized rat

1982 ◽  
Vol 99 (3) ◽  
pp. 437-442 ◽  
Author(s):  
R. J. C. van Straalen ◽  
G. H. Zeilmaker
Keyword(s):  
Pituitary Gland ◽  
Corpus Luteum ◽  
Binding Sites ◽  
Female Rats ◽  
Male Rats ◽  
Rapid Decline ◽  
Corpora Lutea ◽  
Serum Progesterone ◽  
Male And Female Rats ◽  
Hypophysectomized Rats

Abstract. In this study the effects of hypophysectomy and autotransplantation of the pituitary gland on the concentration of hCG-binding sites (LH-receptors) and steroidogenesis in the corpus luteum and the testis of the rat were investigated. It was found that during pseudopregnancy both hCG-binding to homogenates of isolated corpora lutea and the progesterone levels in blood increase until day 7 and subsequently decrease until day 13. Hypophysectomy on day 5 led to a decrease of the number of LH-receptors and the serum progesterone level. By contrast hypophysectomy followed by autotransplantation of the pituitary gland increased the LH-receptor concentration and progesterone synthesis in spite of non-detectable LH-levels. Progesterone implants in hypophysectomized rats did not influence the number of LH-receptors. Hypophysectomy on day 0 without pituitary gland transplantation did not prevent the formation of some luteal LH-receptors measured on day 5 although progesterone was not secreted. A similar effect of prolactin secreted by pituitary autografts on LH-receptors was seen in the testis. The rapid decline of the number of binding sites normally observed after hypophysectomy was prevented by the presence of two pituitary autografts. Testosterone and LH-levels were non-detectable in the operated male rats. These data show that progesterone secretion by the corpora lutea is always associated with the presence of LH-receptors, regardless whether serum LH-levels are detectable or not. Moreover it appears that prolactin maintains or even increases the amount of LH-receptors in hypophysectomized male and female rats.

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.

Sign in / Sign up

Export Citation Format

Share Document