DISSOCIATION IN THE REGULATION OF LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE IN A HYPERPROLACTINAEMIC RAT MODEL: INTERRELATIONSHIPS BETWEEN GONADOTROPHIN AND PROLACTIN CONTROL

1981 ◽  
Vol 90 (1) ◽  
pp. 41-51 ◽  
Author(s):  
J. A. F. TRESGUERRES ◽  
A. I. ESQUIFINO
Keyword(s):  
Positive Feedback ◽  
Follicle Stimulating Hormone ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats ◽  
Oestradiol Benzoate ◽  
Female Wistar Rats ◽  
Pituitary Glands ◽  
Lh Rh ◽  
Lh Releasing Hormone

Male and female Wistar rats were made hyperprolactinaemic by grafting two pituitary glands of litter-mate donors under the kidney capsule at 30 days of age. Other animals were sham-operated at the same age to serve as controls. Plasma levels of prolactin, LH and FSH were measured by double-antibody radioimmunoassay. Basal preoperative prolactin levels of ∼ 10 ng/ml increased after the transplantation in both male and female rats, reaching values of ∼ 180 ng/ml. Levels of LH were significantly reduced in these hyperprolactinaemic rats, whereas an increase in FSH values was seen. After administration of LH releasing hormone (LH-RH) a reduced LH response was seen but there was no response of FSH to LH-RH or even a decrease in FSH values. Prolactin levels were also reduced by LH-RH injection. Although an increase in prolactin levels was observed in control animals after a challenge with oestradiol benzoate, reduced increments were seen in experimental animals. The positive feedback effect of oestradiol benzoate on LH in females was reduced in pituitary-grafted rats but a potentiation of the FSH positive feedback could be clearly detected. This study suggests a dissociation of LH and FSH regulation in hyperprolactinaemia.

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.

Sex- and age-dependent differences in the hormone and drinking responses to water deprivation

2020 ◽  
Vol 318 (3) ◽  
pp. R567-R578 ◽  
Author(s):  
Susana Quirós Cognuck ◽  
Wagner L. Reis ◽  
Marcia S. Silva ◽  
Gislaine Almeida-Pereira ◽  
Lucas K. Debarba ◽  
...  
Keyword(s):  
Water Deprivation ◽  
Plasma Concentrations ◽  
Female Rats ◽  
Male Rats ◽  
Ang Ii ◽  
Adult Males ◽  
Adaptive Responses ◽  
Male And Female ◽  
Male And Female Rats ◽  
Female Wistar Rats

Maintenance of the volume and osmolality of body fluids is important, and the adaptive responses recruited to protect against osmotic stress are crucial for survival. The objective of this work was to compare the responses that occur in aging male and female rats during water deprivation. For this purpose, groups of male and female Wistar rats aged 3 mo (adults) or 18 mo (old) were submitted to water deprivation (WD) for 48 h. The water and sodium (0.15 M NaCl) intake, plasma concentrations of oxytocin (OT), arginine vasopressin (AVP), corticosterone (CORT), atrial natriuretic peptide (ANP), and angiotensin II (ANG II) were determined in hydrated and water-deprived animals. In response to WD, old male and female rats drank less water and saline than adults, and both adult and old females drank more water and saline than respective males. Dehydrated old animals displayed lower ANG II plasma concentration and CORT response compared with the respective normohydrated rats. Dehydrated adult males had higher plasma ANP and AVP as well as lower CORT concentrations than dehydrated adult females. Moreover, plasma OT and CORT levels of old female rats were higher than those in the dehydrated old male rats. Relative expression of ANG II type 1 receptor mRNA was decreased in the subfornical organ of adult and old male rats as well as adult female rats in response to WD. In conclusion, the study elucidated the effect of sex and age on responses induced by WD, altering the degree of dehydration induced by 48 h of WD.

SOME BIOLOGICAL PROPERTIES OF A POTENT FOLLICLE STIMULATING HORMONE PREPARATION

1965 ◽  
Vol 48 (3) ◽  
pp. 439-445 ◽  
Author(s):  
Harold Papkoff
Keyword(s):  
Interstitial Cell ◽  
Follicle Stimulating Hormone ◽  
Intrinsic Property ◽  
Biological Properties ◽  
Female Rats ◽  
Male And Female ◽  
Male And Female Rats ◽  
Stimulating Hormone

ABSTRACT A preparation of ovine follicle stimulating hormone (FSH) which is approximately 50 times as active as NIH-FSH-S1 has been tested in hypophysectomized male and female rats and found to be a potent steroidogenic factor. Contamination of the FSH preparation with interstitial cell-stimulating hormone (ICSH, LH) was found to be very low (0.006–0.016 unit/mg) and could not account for the observed activity. In addition, treatment of the FSH preparation with 6 m urea and neuraminidase indicates that the steroidogenic activity is either an intrinsic property of the FSH molecule or a discrete entity which differs chemically from ICSH.

Effects of oestradiol benzoate on the pituitary-thyroid axis of male and female rats

1983 ◽  
Vol 102 (3) ◽  
pp. 386-391 ◽  
Author(s):  
Rubén Boado ◽  
Edgardo Ulloa ◽  
Angel A. Zaninovich
Keyword(s):  
Corn Oil ◽  
Plasma Concentrations ◽  
Female Rats ◽  
Moderate Degree ◽  
Male And Female ◽  
Male And Female Rats ◽  
Oestradiol Benzoate ◽  
Pituitary Thyroid Axis ◽  
Thyroid Axis ◽  
Thyroid Gland Activity

Abstract. In the present work the effects of oestradiol benzoate (EB) on pituitary and plasma concentrations of TSH, plasma T4 and T3, and thyroidal activity of male and female rats have been studied. Wistar rats weighing between 150 to 200 g were injected sc with varying doses of EB in corn oil for 9 or 30 days. The animals were exsanguinated by cardiac puncture and the hypophyses removed and individually homogenized at 4°C in 200 μl PBS buffer. Pituitary and plasma TSH were measured by radioimmunoassay. Thyroidal activity was evaluated by a 4 h 131I uptake and by 48 h thyroidal release plasma slopes derived form the ratio PB[125I] (from thyroidal secretion) to PB[131I] (from exogenous [131I]T4). In both male and female rats the 10 and 25 μg doses of EB produced a significant decrease in pituitary TSH content; this effect was more pronounced when the 25 μg dose was given over 30 days. Plasma T4 decreased significantly; plasma T3 was moderately elevated in all groups (NS) and significantly increased in female rats treated with 25 μg EB (P < 0.01). It is concluded that EB induced a marked depression of intrapituitary TSH, probably due to a decrease in synthesis, without affecting the release of TSH into the circulation. Moreover, EB accelerated peripheral T4 kinetics and thyroid gland activity, albeit to a moderate degree.

GONADOTROPHIN PATTERNS IN MALE AND FEMALE RATS: PLASMA LH AND FSH AT VARIOUS AGES EVALUATED BY THE METHOD OF PARABIOSIS

1967 ◽  
Vol 56 (1) ◽  
pp. 165-176 ◽  
Author(s):  
Donald C. Johnson
Keyword(s):  
Follicle Stimulating Hormone ◽  
Chorionic Gonadotrophin ◽  
Female Rats ◽  
Adult Males ◽  
Male And Female ◽  
Ovarian Weight ◽  
Average Value ◽  
Male And Female Rats ◽  
Tonic Level ◽  
Males And Females

ABSTRACT Ventral prostates in hypophysectomized male parabiotic partners of intact animals were used to compare the amount of plasma luteinizing hormone (LH) in males and females of various ages. Ovarian weight, histology, and augmentation with chorionic gonadotrophin, in hypophysectomized androgenized females were used to estimate plasma follicle stimulating hormone (FSH) activity in intact adult males and females. In young animals, up to 50 days of age, males apparently have the same amount of plasma LH as females, but older cyclic females produced significantly heavier prostates in their hypophysectomized male partners than did males. The results are consistent with the interpretation that cyclic surges of LH added to a tonic level produced an average value higher for females than males. In contrast, males of all ages and particularly adults, have a significantly greater amount of circulating FSH than females.

An analysis of the course of infection of Moniliformis dubius (Acanthocephala) in rats

Parasitology ◽  
1972 ◽  
Vol 64 (3) ◽  
pp. 517-523 ◽  
Author(s):  
D. W. T. Crompton ◽  
D. E. Walters
Keyword(s):  
Wistar Rats ◽  
Female Rats ◽  
Male Rats ◽  
Male And Female ◽  
Oral Infections ◽  
The Third ◽  
Male And Female Rats ◽  
Female Wistar Rats ◽  
Average Recovery Rate ◽  
Marked Decline

An analysis of the course of infection of mixed oral infections of 12 cystacanths of Moniliformis dubius in 174 male and 179 female Wistar rats has been undertaken.There was a marked decline in the average recovery rate of worms of both sexes from hosts of both sexes during the course of the infection.Female worms from both male and female rats showed, on average, a greater power of survival than male worms from the third period (10–13 weeks) onwards.Male rats were found to retain, on average, a greater number of worms of both sexes than female rats.We wish to thank Miss Susan Arnold and Mr David Barnard for excellent technical help.

scholarly journals Tolerance to hypothermic and antinoceptive effects of Δ9-tetrahydrocannabinol (THC) vapor inhalation in rats

2017 ◽  
Author(s):  
Jacques D. Nguyen ◽  
Yanabel Grant ◽  
Tony M. Kerr ◽  
Arnold Gutierrez ◽  
Maury Cole ◽  
...  
Keyword(s):  
Propylene Glycol ◽  
Wistar Rats ◽  
Female Rats ◽  
Male Rats ◽  
Preclinical Studies ◽  
Male And Female ◽  
Temperature Changes ◽  
Male And Female Rats ◽  
Antinociceptive Effects ◽  
Female Wistar Rats

AbstractRationaleA reduced effect of a given dose of Δ9-tetrahydrocannabinol (THC) emerges with repeated exposure to the drug. This tolerance can vary depending on THC dose, exposure chronicity and the behavioral or physiological measure of interest. A novel THC inhalation system based on e-cigarette technology has been recently shown to produce the hypothermic and antinociceptive effects of THC in rats.ObjectiveTo determine if tolerance to these effects can be produced with repeated vapor inhalation.MethodsGroups of male and female Wistar rats were exposed to 30 minutes of inhalation of the propylene glycol (PG) vehicle or THC (200 mg/mL in PG) two or three times per day for four days. Rectal temperature changes and nociception were assessed after the first exposure on the first and fourth days of repeated inhalation.ResultsFemale, but not male, rats developed tolerance to the hypothermic and antinociceptive effects of THC after four days of twice-daily THC vapor inhalation. Thrice daily inhalation for four days resulted in tolerance in both male and female rats. The plasma THC levels reached after a 30 minute inhalation session did not differ between the male and female rats.ConclusionsRepeated daily THC inhalation induces tolerance in female and male rats, providing further validation of the vapor inhalation method for preclinical studies.AbbreviationsPG, propylene glycol; THC; Δ9tetrahydrocannabinol;

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