scholarly journals Effects of leptin on secretion of LH and FSH from primary cultured female rat pituitary cells

2001 ◽  
Vol 144 (6) ◽  
pp. 653-658 ◽  
Author(s):  
K Ogura ◽  
M Irahara ◽  
M Kiyokawa ◽  
M Tezuka ◽  
T Matsuzaki ◽  
...  
Keyword(s):  
Body Weight ◽  
Wistar Rats ◽  
Pubertal Development ◽  
Reproductive Function ◽  
Female Rats ◽  
Male Rats ◽  
Pituitary Cells ◽  
Female Rat ◽  
Serum Leptin ◽  
Female Wistar Rats

BACKGROUND: Leptin, which is the product of the obese gene, is believed to play important roles in pubertal development and reproductive function in females. In a study using adult male rats, it was found that leptin stimulated secretion of gonadotropin from the pituitary in a dose-related manner. However, there has been no such study in female rats. OBJECTIVE: To investigate the effects of leptin on the production of LH and FSH from the pituitary in female rats, using primary cultured pituitary cells. METHODS: In this study, we determined body weight, serum leptin concentration and serum estradiol (E(2)) concentration in female Wistar rats at 3, 5, 6, 7, 9 and 11 weeks of age, and cultured pituitary cells from 6-week-old female Wistar rats with leptin (0--10(-7) mol/l) and GnRH (0 or 10(-8) mol/l). Then basal and GnRH-stimulated extra- and intracellular LH and FSH were assayed by RIA. RESULTS: Serum leptin concentration increased with increases in body weight and E(2) concentration. The pubertal serum leptin concentration was about 10(-10) mol/l. At a lower or moderate concentration, leptin produced dose-related increases in both basal and GnRH-stimulated extra- and intracellular LH and FSH in pituitary cells. At a concentration of 10 mol/l, leptin significantly (P<0.05) stimulated both basal and GnRH-stimulated extra- and intracellular LH and FSH. However, at greater concentrations, these effects diminished. CONCLUSIONS: These results indicated that leptin induced pituitary cells to produce and secrete both LH and FSH, with or without GnRH. The concentration of leptin that induced the greatest production of gonadotropins by pituitary cells was 10(-10) mol/l, which was the same as the physiological pubertal concentration. Leptin may be involved in the onset of puberty. It is also conceivable that leptin may be a cause of ovulatory failure, not only in weight loss but also in weight gain.

scholarly journals Effects of leptin on gonadotropin secretion in juvenile female rat pituitary cells

2002 ◽  
pp. 261-266 ◽  
Author(s):  
M Tezuka ◽  
M Irahara ◽  
K Ogura ◽  
M Kiyokawa ◽  
T Tamura ◽  
...  
Keyword(s):  
Cultured Cells ◽  
Pubertal Development ◽  
Effective Concentration ◽  
Female Rats ◽  
Pituitary Cells ◽  
Female Rat ◽  
Serum Leptin ◽  
Juvenile Female ◽  
Physiological Serum ◽  
Old Rats

OBJECTIVE: Leptin is an adipocyte-derived hormone, which is the product of the obese gene and it is thought to play important roles in pubertal development and maintenance of reproductive function in the female. In a study using adult male or female rats, it was found that leptin stimulated the secretion of gonadotropin directly from the pituitary in a dose-related manner. However, there is no study in juvenile female rats before puberty. METHODS: In this study, we cultured pituitary cells from 4-, 6- and 8-week-old female Wistar rats with leptin (0-10(-7)mol/l) and gonadotropin-releasing hormone (GnRH) (0 or 10(-8) mol/l). Basal or GnRH-stimulated secretion of luteinizing hormone (LH) and follicle-stimulating hormone (FSH), and their synthesis within cells were determined by radioimmunoassay (RIA). RESULTS: Leptin induced bell-shaped dose--response curves of basal LH and FSH secretion from cultured cells of every age-group of rats studied. The most effective concentration of leptin on the basal secretion of LH and FSH from 6- and 8-week-old cultured pituitary cells was 10(-10) mol/l. This leptin concentration was consistent with circulating physiological serum leptin levels at each age. As for juvenile 4-week-old pituitary cells, the most effective concentration was 10(-11) mol/l which was lower than that of 6- and 8-week-old rats. It was consistent with the circulating serum leptin levels of 4-week-old rats. Also, the synthesis and the GnRH-stimulated secretion of LH and FSH were effectively controlled by leptin at concentrations similar to the serum leptin levels of given ages. CONCLUSIONS: Leptin induced pituitary cells to synthesize and secrete both LH and FSH regardless of the presence or absence of GnRH. The concentration of leptin that induced the greatest synthesis and secretion of gonadotropins from pituitary cells changed around the pubertal period. The most effective leptin concentrations in each experiment were similar to the physiological serum leptin level at each animal age. These results indicate that leptin stimulates gonadotrophs not only in the pubertal and the mature period but also in the juvenile period before puberty. It is also conceivable that leptin may modulate the sensitivity of gonadotrophs until the appearance of GnRH stimulation, and may be the factor that brings about puberty onset.

Hypothalamo-pituitary regulation of the c-myc gene in rat liver

1990 ◽  
Vol 5 (3) ◽  
pp. 267-274 ◽  
Author(s):  
I. Porsch Hällstöm ◽  
J.-Å. Gustafsson ◽  
A. Blanck
Keyword(s):  
Rat Liver ◽  
Female Rats ◽  
Male Rats ◽  
Female Rat ◽  
Continuous Administration ◽  
Gh Secretion ◽  
Cell Proliferation And Differentiation ◽  
Proliferation And Differentiation ◽  
Female Wistar Rats ◽  
Myc Gene

ABSTRACT Expression of the c-myc gene was studied in the livers of male and female Wistar rats. Furthermore, the effects on hepatic c-myc expression of neonatal and adult castration, with or without testosterone supplementation, as well as of continuous administration of GH to intact males, were analysed. Expression of c-myc was low in 6-day-old animals of both sexes, reached a maximum at 35 days of age and declined to the level of adult animals at 70 days. In prepubertal animals, expression was higher in females, but was higher in males after the onset of puberty, the postpubertal female rat liver exhibiting 50–70% of the expression in males. Treatment of adult male rats with bovine GH in osmotic minipumps for 1 week reduced c-myc expression to the level of female rats. Castration, both neonatally and of adults, also feminized hepatic c-myc expression. Testosterone supplementation of the castrated animals increased the expression towards the level in sham-operated controls. These results indicate that the c-myc gene is regulated by the hypothalamo-pituitary-liver axis via the sex-differentiated pattern of GH secretion, in analogy with other sex-differentiated hepatic functions, such as metabolism of steroids and xenobiotics. Neuroendocrine regulation of a gene such as c-myc, which is involved in the control of cell proliferation and differentiation, represents another aspect of the complex influence of GH on various somatic functions.

scholarly journals Reproductive toxicity of triazole fungicides cyproconazole and epoxiconazole when exposed to male and female wistar rats during gametogenesis

2021 ◽  
Vol 54 (1) ◽  
pp. 52-61
Author(s):  
NR Shepelskaya ◽  
YaV Kolyanchuk
Keyword(s):  
Body Weight ◽  
Reproductive Toxicity ◽  
Reproductive Function ◽  
Female Rats ◽  
Male Rats ◽  
Corpora Lutea ◽  
Disruptive Effect ◽  
Male And Female ◽  
Two Samples ◽  
Adverse Effect Level

Aim. Studying the effect of generic pesticides cyproconazole (98 %) and two samples of epoxiconazole (epoxiconazole 1 — 95,75 % and epoxiconazole 2 — 98,7 %) on the reproductive system of male and female Wistar Han rats at the level of the organism when exposed during gametogenesis, identification and characterization of their hazard, as well as assessment of the risk of reproductive toxicity of these compounds. Materials and Methods. The test samples were administered daily (5 days a week) by oral gavage at doses of 0.2 and 2.0 mg/kg for cyproconazole and 0.5 and 2.0 mg/kg for epoxiconazoles during 11 weeks for males, and 10 weeks for females. Also, there were kept intact males and females, intended for crossover mating with experimental animals. After the end of the exposure, functional indicators of the state of the gonads and the ability of animals to reproduce offspring were studied. The duration and the frequency of each stage of the estrous cycle in female rats and the number of motile sperm, the total amount of sperm and the number of abnormal forms of germ cells of the male rats were studied. The reproductive function state in females was evaluated on day 20th of pregnancy. Thereby the number of corpora lutea in the ovaries, number of alive, dead and resorbed foetuses and embryos, the foetus weight, total weight of litters were registered. The studies were carried out in accordance with the recommendations of the Bioethics Commission and the Centre’s standard operating procedures, developed in accordance with the recommendations and requirements of Good Laboratory Practice (GLP). Conclusions. Test substances at a maximum dose of 2.0 mg/kg of body weight have reproductive toxicity and endocrine-disruptive effect, exerting a significant antiandrogenic effect on males and antiestrogenic effect on female rats. No-observed-adverse-effect-level (NOАEL) for gonadal and reproductive toxicity for male and female Wistar Han rats were established. They are 0.2 mg/kg body weight for cyproconazole and 0.5 mg/kg body weight for epoxiconazole. Key Words: azole fungicides, cyproconazole, epoxiconazole, reproductive toxicity, antiandrogenic and antiestrogenic effects, Wistar Han rats.

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;

scholarly journals Effect of Penicillin on Reproductive Function in Female Wistar Rats

2021 ◽  
Vol 71 (2) ◽  
Author(s):  
Oyedeji K.O ◽  
Momoh R.O ◽  
Oderinde Gbenga
Keyword(s):  
Estrous Cycle ◽  
Wistar Rats ◽  
Reproductive Function ◽  
Daily Basis ◽  
Female Rats ◽  
Histopathological Study ◽  
Fertility Effect ◽  
Female Wistar Rats ◽  
Student’S T ◽  
Histopathological Studies

This study was designed to investigate the effect of penicillin on reproductive function in female Wistar rats. Fifteen female rats (120 – 160 g) were used for the estrous cycle and histopathological studies. Penicillin (17.14 mg/kg) was administered orally on daily basis for 21 and 50 days respectively for the estrous cycle and histological studies. Estrous cycle was carried out using the technique of Marcondes et al., histologies of the ovaries and uteri were also carried out. Data were analysed using descriptive statistics and student’s t-test at p=0.05. Treatment of rats for 21 days with penicillin (17.14 mg/kg) produced significant (p<0.05) increments in the estrous and metestrous phases as well as a significant (p<0.05) reduction in the proestrous phase of the estrous cycle relative to their respective controls. The histopathological study presented with a moderate endometrial congestion. It can therefore be concluded that penicillin probably has a pro-fertility effect with a moderate deleterious effect on the uteri at histological level in female Wistar rats.

scholarly journals CORRELATION OF GENDER AND LEPTIN WITH ANALGESIC EFFECT OF TRAMADOL IN RATS

2018 ◽  
Vol 11 (6) ◽  
pp. 493
Author(s):  
Shakta Mani Satyam ◽  
Laxminarayana Kurady Bairy ◽  
Vasudha Devi
Keyword(s):  
Acetic Acid ◽  
Correlation Coefficient ◽  
Wistar Rats ◽  
Pearson Correlation ◽  
Female Rats ◽  
Male Rats ◽  
Control Group ◽  
Pearson Correlation Coefficient ◽  
Serum Leptin ◽  
Plantar Test

 Objective: The objective of the study was to investigate the correlation of gender and serum leptin level with analgesic modulation of tramadol in Wistar rats.Methods: A total of 48 Wistar rats (body weight 100–150 g), 24 each male and female Wistar rats were randomly divided into two groups (n=6/group) (Group I - Control- 0.9% NaCl; 1 ml/kg/day i.p. and Group II - Tramadol 10 mg/kg/day i.p.) for each nociception model - plantar test and acetic acid induced writhing test. The treatment duration was of 5 days. Paw withdrawal latency (PWL) was assessed using plantar test and writhing movements were observed following administration of 0.8% acetic acid; 10 ml/kg i.p.Results: PWL was significantly decreased (p<0.001) and both number of writhing movements and serum leptin concentrations were significantly increased (p<0.001) in female control group compared to male control group. In tramadol treated female rats, PWL was significantly decreased (p=0.005) and both number of writhing movements and serum leptin concentrations were significantly increased (p<0.001) in comparison with the tramadol treated male rats. PWL was negatively correlated with serum leptin concentration (Pearson correlation coefficient= −0.826, two-tailed significance= 0.000), and writhing movements were positively correlated with serum leptin concentration (Pearson correlation coefficient= 0.505, two-tailed significance= 0.012).Conclusions: The present study revealed that female rats have more serum leptin concentration than male rats which could be one of the possible reasons for having more pain sensitivity to noxious stimuli in female rats compared to male rats. Tramadol treatment at the dose of 10 mg/kg for 5 days has decreased serum leptin level in rats which might be one of the additional mechanisms of tramadol to reduce pain.

scholarly journals Regulation of serum leptin levels by gonadal function in rats

1999 ◽  
pp. 468-473 ◽  
Author(s):  
L Pinilla ◽  
LM Seoane ◽  
L Gonzalez ◽  
E Carro ◽  
E Aguilar ◽  
...  
Keyword(s):  
Body Weight ◽  
Estrous Cycle ◽  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Internal Diameter ◽  
External Diameter ◽  
Gonadal Function ◽  
Intact Male ◽  
Serum Leptin

The aim of this study was to investigate the regulation of serum leptin levels by gender and gonadal steroid milieu. Thus, we measured serum leptin levels by radioimmunoassay in (a) intact male and female rats, (b) female rats at different stages of the estrous cycle and (c) ovariectomized or orchidectomized rats. Gonadectomized groups were or were not implanted with silastic capsules (10 or 30 mm in length, 1.519mm internal diameter; 3.06 mm external diameter) containing estradiol or testosterone and decapitated two weeks later. We found (i) intact female rats weighing 50 g, 250 g and 300 g exhibited higher serum leptin concentrations than intact male rats of similar body weight; (ii) leptin concentrations were not affected by the phase of the estrous cycle; (iii) two weeks after gonadectomy serum leptin concentrations increased in both male (from 4.47+/-1.87 to 8.76+/-1.24 ng/ml) and female (from 1.97+/-0.46 to 5.29+/-0.51 ng/ml) rats. The ovariectomy-induced increase in serum leptin levels was not dependent, at least completely, on changes in body weight since it could be observed when comparisons were made between ovariectomized rats and intact rats in estrus matched for body weight. In contrast the effect of orchidectomy on serum leptin levels appears to be dependent on changes in body weight since it was no longer observed when comparisons were made with a group of intact male rats matched for body weight. In conclusion, these results suggest that serum leptin concentrations are controlled by gonadal function either directly or as a consequence of changes in body weight.

scholarly journals Histological and hormonal studies of calabash chalk on ovarian function in adult female wistar rats

2017 ◽  
Vol 34 (03) ◽  
pp. 173-177
Author(s):  
A. Oyewopo ◽  
K. Obasi ◽  
K. Anumudu ◽  
E. Yawson
Keyword(s):  
Body Weight ◽  
Adult Female ◽  
Wistar Rats ◽  
Ovarian Function ◽  
Female Rats ◽  
Control Group ◽  
Treatment Groups ◽  
Female Wistar Rats ◽  
Group A ◽  
Group B

Abstract Introduction: Calabash chalk is a naturally occurring mineral, chiefly composed of fossilized sea shells. It is prepared from clay and mud mixed with other ingredients, including lead, arsenic, sand and wood ash. Clay consumption is correlated with pregnancy, and also to eliminate morning sickness in women. The aim of this study is to evaluate the effects of calabash chalk on the ovarian function in adult female Wistar rats. Methods: Eighteen (18) adult female Wistar rats. Group A served as the control group, group B received 40 mg/kg body weight of Non-salted calabash chalk while group C received 40 mg/kg body weight of Salted calabash chalk for 14 days. On day 15, the animals were sacrificed for histological and biochemical examination. Results: Results showed a significant (P< 0.05) reduction in follicle stimulating hormone (FSH) levels of the treatment groups when compared with the control group and an increase in luteinizing hormone (LH) levels of the treatment groups when compared with the control group. Histological examination of the ovaries showed severe deterioration of the ovarian follicles, necrosis and follicular atresia. Conclusion: Calabash chalk is toxic to ovarian function. These alterations have been shown to be the leading cause ofinfertility in female rats. Hence, proper monitoring, education, and regulation of the product is needed.

scholarly journals Potential galactogogues effect of Silymarin: An experimental study in female rats

2014 ◽  
Vol 13 (1) ◽  
pp. 32
Author(s):  
B. I. Mohammed
Keyword(s):  
Group Treatment ◽  
Prolactin Level ◽  
Wistar Rats ◽  
Pregnant Female ◽  
Female Rats ◽  
Serum Prolactin ◽  
Female Rat ◽  
Serum Prolactin Level ◽  
Body Weights ◽  
Female Wistar Rats

The study aimed to evaluate the galactogogues effect of Silymarin in pregnant and lactating female rats. A total of 72 pregnant female Wistar rats randomly divided into 3 groups (24 rats of each). Rats in first group used as control, received drinking water daily for 14 days from 8th day of gestation till the delivery, while the animals in second group, received Metoclopramide (5mg\kg\day) as the same period. In addition to Silymarin group (treatment group) received Silymarin (200 mg\kg\day) as the same period. Dams’ body weights have been monitored throughout the pregnancy. At the first day of parturition, litter weights have been measured, and (8) animals of each groups were sacrificed, blood sample were collected to measure the serum prolactin level. In addition, the litters were allocated in to (8) litters per lactated dam. Then each group sub divided in to two sub groups A and B according to continue or discontinue of received drugs, for 11days from parturition. Silymarin in a dose (200mg\kg) was significantly increase litters body weight and serum prolactin level in pregnant female rat (p< 0.05) in compared with control and Metoclopramide groups. Silymarin and Metoclopramide during the eleventh day of lactation registered significant differences (P<0.05) in their serum prolactin concentration, litters weight gain compared with that stopped in receiving the treatment in the same group, whereas control subgroups revealed no significant (P>0.05) differences when compared with each other. It can be concluded that Silymarin has potential glactogoguse effect and enhance milk production

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