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

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.

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.

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 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.

scholarly journals Gender Differences in the Effect of Prenatal Methamphetamine Exposure and Challenge Dose of Other Drugs on Behavior of Adult Rats

2013 ◽  
pp. S99-S108 ◽  
Author(s):  
R. ŠLAMBEROVÁ ◽  
E. MACÚCHOVÁ ◽  
K. NOHEJLOVÁ-DEYKUN ◽  
B. SCHUTOVÁ ◽  
L. HRUBÁ ◽  
...  
Keyword(s):  
Estrous Cycle ◽  
Adult Male ◽  
Gonadal Hormones ◽  
Female Rats ◽  
Male Rats ◽  
Prenatally Exposed ◽  
Challenge Dose ◽  
Adult Rats ◽  
Male And Female ◽  
Male And Female Rats

The aim of the present study was to compare the response to acute application of several drugs in adult male and female rats prenatally exposed to methamphetamine (MA). Spontaneous locomotor activity and exploratory behavior of adult male and female rats prenatally exposed to MA (5 mg/kg) or saline were tested in a Laboras apparatus (Metris B.V., Netherlands) for 1 h. Challenge dose of the examined drug [amphetamine – 5 mg/kg; cocaine – 5mg/kg; MDMA (3,4-methylenedioxymethamphetamine) – 5 mg/kg; morphine – 5 mg/kg; THC (delta9-tetrahydrocannabinol) – 2 mg/kg] or saline was injected prior to testing. Our data demonstrate that prenatal MA exposure did not affect behavior in male rats with cocaine or morphine treatment, but increased locomotion and exploration in females. Application of amphetamine and MDMA in adulthood increased activity in both sexes, while cocaine and THC only in female rats. Morphine, on the other hand, decreased the activity in the Laboras test in both sexes. As far as sex and estrous cycle is concerned, the present study shows that males were generally less active than females and also females in proestrus-estrus phase of the estrous cycle were more active than females in diestrus. In conclusion, the present study shows that the prenatal MA exposure does not induce general sensitization but affects the sensitivity to drugs dependently to mechanism of drug action and with respect to gonadal hormones.

Hyperprolactinaemia attenuates the gonadotrophin releasing hormone receptor response to gonadectomy in rats

1982 ◽  
Vol 95 (2) ◽  
pp. 267-274 ◽  
Author(s):  
R. N. Clayton ◽  
L. C. Bailey
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Serum Prolactin ◽  
Intact Male ◽  
Adult Rats ◽  
Releasing Hormone ◽  
Receptor Response ◽  
Serum Lh ◽  
Gonadotrophin Releasing Hormone ◽  
Qualitative Index

Measurement of pituitary gonadotrophin releasing hormone (Gn-RH) receptor content provides a qualitative index of prior exposure of the pituitary gland to endogenous Gn-RH. The effect of moderate hyperprolactinaemia (serum prolactin = 95–250 μg/l), achieved with three pituitary grafts beneath the renal capsule, on the pituitary Gn-RH receptor content and serum LH responses to gonadectomy of adult rats has been studied. In males the presence of hyperprolactinaemia for 7 days completely prevented the increase in Gn-RH receptor content 3 days after castration and inhibited the serum LH rise by 45%. By 6 days after castration, Gn-RH receptors had increased in the hyperprolactinaemic castrated animals but values were 33% lower than in sham-grafted controls, while the serum LH increase was attenuated by 30%. Pituitary LH content was also lower in grafted castrated animals 6 days after castration. Hyperprolactinaemia for 3 weeks had no effect on Gn-RH receptors or pituitary LH content of intact male rats, although basal serum LH was decreased by 50%. Hyperprolactinaemia also attenuated the increases in Gn-RH receptors, serum LH and pituitary LH which occurred 6 days after ovariectomy in female rats. In all experiments the pituitary content of prolactin was reduced by 80–90% in animals bearing pituitary grafts. These results suggest that hyperprolactinaemia restricts the Gn-RH receptor response to gonadectomy by decreasing endogenous hypothalamic Gn-RH secretion.

Phosphatidylinositol 4,5-bisphosphate stimulates alveolar epithelial fluid clearance in male and female adult rats

2011 ◽  
Vol 301 (5) ◽  
pp. L804-L811 ◽  
Author(s):  
Edgar E. Kooijman ◽  
Stephanie R. Kuzenko ◽  
Denghuang Gong ◽  
Michael D. Best ◽  
Hans G. Folkesson
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Na Channel ◽  
Alveolar Fluid Clearance ◽  
Membrane Phospholipids ◽  
Adult Rats ◽  
Male And Female ◽  
Alveolar Epithelial ◽  
Male And Female Rats

Cell membrane phospholipids, like phosphatidylinositol 4,5-bisphosphate [PI( 4 , 5 )P2], can regulate epithelial Na channel (ENaC) activity. Gender differences in lung ENaC expression have also been demonstrated. However, the effects in vivo on alveolar fluid clearance are uncertain. Thus PI( 4 , 5 )P2 effects on alveolar fluid clearance were studied in male and female rats. An isosmolar 5% albumin solution was intrapulmonary instilled; alveolar fluid clearance was studied for 1 h. Female rats had a 37 ± 19% higher baseline alveolar fluid clearance than male rats. Bilateral ovariectomy attenuated this gender difference. Compared with controls, PI( 4 , 5 )P2 instillation (300 μM) increased alveolar fluid clearance by ∼93% in both genders. Amiloride or the specific αENaC small-interfering RNA inhibited baseline and PI( 4 , 5 )P2-stimulated alveolar fluid clearance in both genders, indicating a dependence on amiloride-sensitive pathways. The fraction of amiloride inhibition was greater in PI( 4 , 5 )P2-instilled rats (male: 64 ± 10%; female: 70 ± 11%) than in controls (male: 30 ± 6%; female: 44 ± 8%). PI( 4 , 5 )P2 instillation lacked additional alveolar fluid clearance stimulation above that of terbutaline, nor did propranolol inhibit alveolar fluid clearance after PI( 4 , 5 )P2 instillation, indicating that PI( 4 , 5 )P2 stimulation was not secondary to endogenous β-adrenoceptor activation. PI( 4 , 5 )P2 amine instillation resulted in an intermediate alveolar fluid clearance stimulation, suggesting that, to reach maximal alveolar fluid clearance stimulation, PI( 4 , 5 )P2 must reside in cell membranes. In summary, PI( 4 , 5 )P2 instillation upregulated in vivo alveolar fluid clearance similar to short-term β-adrenoceptor upregulation of alveolar fluid clearance. PI( 4 , 5 )P2 stimulation was mediated partly by increased amiloride-sensitive Na transport. There exist important gender-related effects suggesting a female advantage that may have clinical implications for resolution of acute lung injury.

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.

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.

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.

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