SERUM GONADOTROPHIN LEVELS DURING DEVELOPMENT IN MALE, FEMALE AND ANDROGENIZED FEMALE RATS AND THE EFFECT OF GENERAL DISTURBANCE ON HIGH LUTEINIZING HORMONE LEVELS

1976 ◽  
Vol 70 (3) ◽  
pp. 361-371 ◽  
Author(s):  
P. C. B. MACKINNON ◽  
J. M. MATTOCK ◽  
M. B. TER HARR
Keyword(s):  
Wistar Rats ◽  
High Serum ◽  
Female Rats ◽  
Serum Prolactin ◽  
Adult Males ◽  
Serum Lh ◽  
Male Wistar Rats ◽  
Serial Blood Sampling ◽  
Lh Release ◽  
Very High

SUMMARY Serum LH, FSH and prolactin levels were measured in blood samples which were obtained by decapitation from groups of female, neonatally androgenized female and male Wistar rats at 2-day intervals from birth to maturity. An increase in serum FSH levels was observed between 4 and 24 days of age in both the female and androgenized female groups, while a much later increase, between 28 and 44 days of age, occurred in the males. Serum prolactin levels increased gradually from birth in all three groups until adult levels were attained. In contrast, serum LH levels were in general low in all three groups of animals, although very high levels (> 7 ng/ml) were recorded in 22 out of 168 females and 8 out of 192 males between 4 and 28 days of age, as well as in adult males; occasional high LH levels were also seen in the androgenized females. The nature of the high serum LH levels was investigated in anaesthetized and unanaesthetized immature females by serial blood sampling using a number of techniques. Unexpectedly, only three out of 58 animals had high LH levels: two of these showed an episodic form of LH release during which levels increased to peak values and then declined within a period of about 30 min. On investigation it was found that general disturbance within the 45 min before decapitation could inhibit high LH levels in females aged between 23 and 30 days.

ANTIGONADOTROPHIC EFFECT OF PROLACTIN IN ADULT CASTRATED AND IN IMMATURE FEMALE RATS

1977 ◽  
Vol 84 (1) ◽  
pp. 62-71 ◽  
Author(s):  
W. Beck ◽  
S. Engelbart ◽  
M. Gelato ◽  
W. Wuttke
Keyword(s):  
High Serum ◽  
Female Rats ◽  
Serum Prolactin ◽  
Intact Female ◽  
Immature Female ◽  
Blood Samples ◽  
Serum Lh ◽  
Male Donor ◽  
Lh Release ◽  
Timing Of Puberty

ABSTRACT High serum prolactin levels were induced in chronically castrated female rats by pituitary transplants from male donor rats. The typical pulsatile LH release pattern observed in castrated control rats was maintained in pituitary grafted rats, when pituitary transplantation was performed simultaneously with castration 3 months before withdrawal of the blood samples. If pituitaries were transplanted into chronically castrated rats and blood samples were withdrawn 3 days later, the pulsatile LH release was abolished and basal or moderately elevated LH levels were found. Chronically or subacutely elevated prolactin levels had no effect on high serum FSH values. Pituitary transplants into intact female rats at day 23 after birth also suppressed basal LH values for 4 days without alterating the serum FSH levels. Six and 8 days after transplantation the serum LH levels were normal. Pituitary transplantation into these immature rats advanced puberty by more than one week. These results indicate that prolactin has an antigonadotrophic effect in female rats which is directed only towards pituitary LH but not FSH secretion. The inhibitory action of high serum prolactin levels on pituitary LH release does not last longer than 4–6 days under steady state conditions, such as found in the constantly high prolactin levels due to pituitary transplants. Under natural conditions with steadily increasing prolactin levels between day 20 and puberty the effect of prolactin in inhibiting pituitary LH release may last longer. Thus, prolactin may be one of the, if not the regulator of the timing of puberty.

EFFECTS OF NALOXONE ON LUTEINIZING HORMONE AND PROLACTIN IN SERUM OF RATS

1980 ◽  
Vol 85 (2) ◽  
pp. 307-315 ◽  
Author(s):  
M. S. BLANK ◽  
A. E. PANERAI ◽  
H. G. FRIESEN
Keyword(s):  
Female Rats ◽  
Male Rats ◽  
Ovariectomized Rats ◽  
Serum Prolactin ◽  
Immature Female ◽  
Subcutaneous Injections ◽  
Serum Lh ◽  
Opiate Peptides ◽  
Lh Release ◽  
Lh Secretion

The effects of subcutaneous injections of the opiate antagonist naloxone on the tonic and phasic secretion of prolactin and LH were studied in rats. During development, resting levels of prolactin in serum were decreased by naloxone (2·5 mg/kg body wt) on days 24,45 and 50 in female rats and on days 28,45 and 50 in male rats. In the adult, naloxone (2·5 mg/kg body wt) decreased basal levels of serum prolactin in male rats and levels during oestrus in female rats. In 25-day-old female rats, serum LH rose from resting levels within 7·5 min of naloxone administration (2·5 mg/kg body wt) and returned to pretreatment levels by 30 min, while prolactin fell by 7·5 min and remained low for as long as 60 min after treatment. Furthermore, a tenfold lower dose of naloxone (0·25 mg/kg body wt) did not raise basal levels of serum LH but still decreased resting levels of serum prolactin in immature female rats (24 days old). The effect of naloxone (2·5 mg/kg body wt) on phasic LH release was studied in 29-day-old immature female rats primed on day 27 with pregnant mare serum gonadotrophin (PMSG). In these PMSG-treated rats the onset of the prolactin surge was blunted by naloxone while it had no effect on phasic LH release. Naloxone (5 mg/kg body wt) also induced a rise in levels of serum LH in ovariectomized rats and, if administered with morphine, it reversed the short-term inhibition of LH secretion caused by morphine. However, naloxone was ineffective after pretreatment with oestradiol benzoate. These findings suggest that the responses of serum LH and prolactin to naloxone were dissociated and that oestrogens and opiate peptides may have interacted to regulate secretion of LH.

Hormone concentrations and ovulatory response in rats treated with antiprogestagens

1991 ◽  
Vol 129 (3) ◽  
pp. 423-429 ◽  
Author(s):  
J. Th. J. Uilenbroek
Keyword(s):  
Cumulus Cells ◽  
High Serum ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Ovulation Rate ◽  
Female Rats ◽  
Serum Prolactin ◽  
Lh Surge ◽  
Serum Lh ◽  
Preovulatory Follicles

ABSTRACT Administration of antiprogestagens (2 mg/day) to female rats for 21 days induces high serum prolactin levels. These levels stimulate luteal progesterone production and an increase in ovarian weight. Compared with RU486 (mifepristone) the increase in prolactin is less after treatment with ZK299 (onapristone), an antiprogestagen with lower antiglucocorticoid activity. To study whether cyclic ovulations occur in rats treated with antiprogestagens, 5-day cyclic rats were given daily injections of RU486 or ZK299 (2 mg) from metoestrus (day 1) to pro-oestrus. This treatment advanced the forthcoming ovulation by 1 day; however, the ovulation rate was low. Injection of 10 IU human chorionic gonadotrophin on the afternoon of pro-oestrus (day 3) increased the ovulation rate, but not to the level found in oil-treated rats. Serum LH concentrations measured from metoestrus to oestrus at 10.00 and 17.00 h were higher in antiprogestagen- than in oil-treated rats from day 2 (17.00 h) onwards. A low preovulatory LH surge was found in antiprogestagen-treated rats on the after-noon of pro-oestrus (day 3). Ovarian histology at the day of oestrus (day 4) confirmed the presence of a low LH surge as, besides ruptured follicles, unruptured follicles with dispersion of cumulus cells were present. The pro-oestrous surge of prolactin was also advanced by 24 h. The magnitude, however, was not different from that in oil-treated rats at day 4. In conclusion, daily administration of antiprogestagens to 5-day cyclic rats results in increased basal levels of serum LH and advancement of the preovulatory surge of prolactin and LH by 1 day. The ovulatory response is low due to the low pre-ovulatory surge of LH and to a reduced ability of preovulatory follicles to respond to LH. Journal of Endocrinology (1991) 129, 423–429

OESTROGENS AND PROLACTIN AS POSSIBLE REGULATORS OF PUBERTY

1976 ◽  
Vol 68 (3) ◽  
pp. 391-396 ◽  
Author(s):  
W. WUTTKE ◽  
K. D. DÖHLER ◽  
M. GELATO
Keyword(s):  
Positive Feedback ◽  
High Serum ◽  
Female Rats ◽  
Serum Prolactin ◽  
Early Puberty ◽  
Control Female ◽  
Highly Sensitive ◽  
Specific Antisera ◽  
Lh Release ◽  
Ovine Prolactin

SUMMARY At day 15 after birth, high serum oestradiol levels, high FSH levels and occasionally high LH levels were observed in control female rats. Injections of potent and specific antisera for oestrogen between days 8–15 prevented LH peaks and decreased basal LH levels. Serum FSH levels were increased after treatment. High oestradiol levels at this time appear to exert a positive feedback action on phasic as well as tonic LH release. Injections of ovine prolactin (0·5 μg/g body wt twice daily) between days 8–25 of life significantly advanced the day of vaginal opening in immature rats and initiated regular oestrous cycles. Such treatment completely prevented high LH levels at day 15 but serum FSH levels remained high. Prolactin and progesterone levels were higher at day 25 than at day 15 in control rats and at that time LH and FSH levels were low. Prolactin treatment had a depressant effect on endogenous prolactin and progesterone levels. It is proposed that after day 20 the positive feedback threshold of oestradiol on LH release is at a mature, highly sensitive level. The steady increment in serum prolactin and/or progesterone levels between day 20 and puberty, however, inhibited phasic LH release thus preventing early puberty. The possible mechanisms of action of prolactin are discussed.

Leptin administration during lactation leads to different nutritional, biometric, hemodynamic, and cardiac outcomes in prepubertal and adult female Wistar rats

2021 ◽  
pp. 1-6
Author(s):  
Karyne Pollo de Souza ◽  
Samuel de Sousa Pedro ◽  
Nazareth Novaes Rocha ◽  
Emiliana Barbosa Marques ◽  
Christianne Bretas Vieira Scaramello
Keyword(s):  
Left Ventricle ◽  
Test Performance ◽  
Wistar Rats ◽  
Female Rats ◽  
Internal Diameter ◽  
Critical Periods ◽  
Adult Age ◽  
Cardiac Outcomes ◽  
Male Wistar Rats ◽  
Echocardiographic Parameters

Abstract Literature reports that insults, such as hormonal disturbances, during critical periods of development may modulate organism physiology and metabolism favoring cardiovascular diseases (CVDs) later in life. Studies show that leptin administration during lactation leads to cardiovascular dysfunction in young and adult male Wistar rats. However, there are sex differences regarding CVD. Thus, the present work aimed to investigate neonatal leptin administration’s consequences on different outcomes in female rats at prepubertal and adult age. Newborn Wistar female rats were divided into two groups, Leptin and Control, receiving daily subcutaneous injections of this adipokine (8 μg/100 g) or saline for the first 10 of 21 d of lactation. Nutritional, biometric, hemodynamic, and echocardiographic parameters, as well as maximal effort ergometer performance, were determined at postnatal days (PND) 30 and 150. Leptin group presented lower food intake (p = 0.0003) and higher feed efficiency (p = 0.0058) between PND 21 and 30. Differences concerning echocardiographic parameters revealed higher left ventricle internal diameter (LVID) in systole (p = 0.0051), as well as lower left ventricle ejection fraction (LVEF) (p = 0.0111) and fractional shortening (FS) (p = 0.0405) for this group at PND 30. Older rats treated with leptin during lactation presented only higher LVID in systole (p = 0.0270). Systolic blood pressure and maximum effort ergometer test performance was similar between groups at both ages. These data suggest that nutritional, biometric, and cardiac outcomes due to neonatal leptin administration in female rats are age-dependent.

scholarly journals Effects of a new thyrotropic drug isolated from Potentilla alba on the male reproductive system of rats and offspring development

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lubov V. Krepkova ◽  
Valentina V. Bortnikova ◽  
Aleksandra N. Babenko ◽  
Praskovya G. Mizina ◽  
Vladimir A. Mkhitarov ◽  
...  
Keyword(s):  
Animal Study ◽  
Male Fertility ◽  
Wistar Rats ◽  
Medical Condition ◽  
Adverse Outcomes ◽  
Female Rats ◽  
Childbearing Age ◽  
Offspring Development ◽  
Male Wistar Rats ◽  
And Control

Abstract Background The dysfunction of the thyroid gland is a common medical condition. Nowadays, patients frequently use medicinal herbs as complementary or alternative options to conventional drug treatments. These patients may benefit from treatment of thyroid dysfunctions with Potentilla alba L. preparations. While it has been reported that Potentilla alba preparations have low toxicity, nothing is known about their ability to affect reproductive functions in patients of childbearing age. Methods Male Wistar rats were orally treated with a thyrotrophic botanical drug, standardized Potentilla alba Dry Extract (PADE), at doses 8 and 40 times higher than the median therapeutic dose recommended for the clinical trials, for 60 consecutive days. Male Wistar rats receiving water (H2O) were used as controls. After completing treatment, half of the PADE-treated and control males were used to determine PADE gonadotoxicity, and the remaining half of PADE-treated and control males were mated with intact females. Two female rats were housed with one male for two estrus cycles. PADE effects on fertility and fetal/offspring development were evaluated. Results Herein, we report that oral treatment of male Wistar rats with PADE before mating with intact females instigated marked effects on male reproductive organs. Treatment significantly decreased the motility of the sperm and increased the number of pathological forms of spermatozoa. Additionally, a dose-dependent effect on Leydig cells was observed. However, these PADE effects did not significantly affect male fertility nor fetal and offspring development when PADE-treated males were mated with intact females. Conclusions PADE treatment of male rates negatively affected sperm and testicular Leydig cell morphology. However, these changes did not affect male fertility and offspring development. It is currently not known whether PADE treatment may affect human male fertility and offspring development. Therefore, these results from an animal study need to be confirmed in humans. Results from this animal study can be used to model the exposure-response relationship and adverse outcomes in humans.

Changes in the characteristics of pulsatile luteinizing hormone secretion during the oestrous cycle and after ovariectomy and oestrogen treatment in female rats

1982 ◽  
Vol 94 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Takashi Higuchi ◽  
Masazumi Kawakami
Keyword(s):  
Hormone Secretion ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Oestrous Cycle ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Luteinizing Hormone Secretion ◽  
Oestrogen Treatment ◽  
Serum Lh ◽  
Lh Release

Changes in the characteristics of LH secretory pulses in female rats were determined in different hormonal conditions; during the oestrous cycle and after ovariectomy and oestrogen treatment. The frequency and amplitude of the LH pulses were stable during the oestrous cycle except at oestrus when a pattern could not be discerned because of low LH concentrations. These were significantly lower than those measured during other stages of the cycle. Mean LH concentrations and LH pulse amplitudes increased with time up to 30 days after ovariectomy. The frequency of the LH pulse was unchanged 4 days after ovariectomy when mean LH levels had already increased. The frequency increased 10 days after ovariectomy and then remained stable in spite of a further increase in mean serum LH concentrations. Oestradiol-17β injected into ovariectomized rats caused a decrease in LH pulse amplitude but no change in pulse frequency. One day after treatment with oestradiol benzoate no LH pulse was detectable, probably because the amplitude was too small. A generator of pulsatile LH release is postulated and an oestrogen effect on its function is discussed.

RESTORATION OF OESTROGEN POSITIVE FEEDBACK EFFECT ON LH RELEASE BY BROMOCRIPTINE IN HYPERPROLACTINAEMIC PATIENTS WITH GALACTORRHOEA-AMENORRHOEA

1979 ◽  
Vol 91 (3) ◽  
pp. 591-600 ◽  
Author(s):  
Toshihiro Aono ◽  
Akira Miyake ◽  
Takenori Shioji Motoi Yasuda ◽  
Koji Koike ◽  
Keiichi Kurachi
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Serum Prolactin ◽  
Serum Luteinizing Hormone ◽  
Serum Lh ◽  
Lh Release ◽  
The Mean ◽  
Lh Rh ◽  
Lh Releasing Hormone ◽  
Positive Feedback Effect

ABSTRACT Five mg of bromocriptine was administered for 3 weeks to 8 hyperprolactinaemic women with galactorrhoea-amernorrhoea, in whom the response of serum luteinizing hormone (LH) and follicle-stimulating hormone (FSH) to 100 μg of iv LH-releasing hormone (LH-RH) had been evaluated. Twenty mg of conjugated oestrogen (Premarin®) was injected iv any day between the 10th and 12th day from the initiation of the treatment, and serum LH levels were serially determined for 120 h. Hyperresponse of LH with normal FSH response to LH-RH was observed in most patients. Bromocriptine treatment for 10 to 12 days significantly suppressed mean (± se) serum prolactin (PRL) levels from 65.1 ± 23.0 to 10.4 ± 2.0 ng/ml, while LH (12.6 ± 2.1 to 24.8 ± 5.9 mIU/ml) and oestradiol (40.1 ± 7.6 to 111.4 ± 20.8 pg/ml) levels increased significantly. Patients on bromocriptine treatment showed LH release with a peak at 48 h after the injection of Premarin. The mean per cent increases in LH were significantly higher than those in untreated patients with galactorrhoea-amenorrhoea between 32 and 96 h after the injection. The present results seem to suggest that the restoration of LH-releasing response to oestrogen following suppression of PRL by bromocriptine may play an important role in induction of ovulation in hyperprolactinaemic patients with galactorrhoea-amenorrhoea.

scholarly journals Commercial Formulation of Chlorpyrifos Alters Neurological Behaviors and Fertility

Biology ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 49
Author(s):  
Enoka P. Kudavidanage ◽  
D. M. I. Dissanayake ◽  
W. L. Rangi Keerthirathna ◽  
N. Lasni Wathima Nishshanke ◽  
L. Dinithi C. Peiris
Keyword(s):  
Wistar Rats ◽  
Serum Testosterone ◽  
Female Rats ◽  
Male Rats ◽  
Risk Minimization ◽  
Commercial Formulation ◽  
Male Wistar Rats ◽  
Neurological Alterations ◽  
Implantation Sites ◽  
Androgen Levels

Pesticides are known to result in toxic insult. We aimed to evaluate Judo 40, the commercial formulation of chlorpyrifos on the neurological activities, fertility, and hormone levels of male rats. Male Wistar rats were treated orally with 1 mL of 20 or 50 mg/kg Judo 40. The doses were administered four times, twice a day. Sexual and exploratory behavior indices, fertility indices, serum androgen levels, blood acetylcholinesterase (BChE) levels, and neurological and muscular effects were evaluated. Serum testosterone and luteinizing hormone were significantly reduced in the rats receiving 50 mg/kg Judo 40. A reduction in viable implantation sites and live pups born were evident in the female rats mated with the male rats treated with the highest dose. Similarly, in the rats treated with the highest dose of Judo 40, a significant reduction in plasma BChE enzyme was observed. According to the results, prolonged Judo 40 exposure can cause impairment of the neurological alterations and sex hormones leading to impaired fertility. Therefore, chemical handlers should be educated on protection and risk minimization.

THE SEQUENCE OF HORMONAL CHANGES DURING PROSTAGLANDIN INDUCED LUTEOLYSIS OF THE SUPERLUTEINIZED RAT OVARY

1978 ◽  
Vol 87 (3) ◽  
pp. 617-624 ◽  
Author(s):  
P. A. Torjesen ◽  
R. Dahlin ◽  
E. Haug ◽  
A. Aakvaag
Keyword(s):  
Binding Sites ◽  
Limit Of Detection ◽  
Serum Levels ◽  
Female Rats ◽  
Serum Prolactin ◽  
Hormonal Changes ◽  
Subsequent Increase ◽  
Serum Progesterone ◽  
Serum Lh ◽  
Prostaglandin F

ABSTRACT Immature female rats were pre-treated with pregnant mare's serum gonadotrophin (PMSG) and human chorionic gonadotrophin (HCG) to achieve superluteinization. Eight days after the HCG administration luteolysis was induced by sc injection of 5 μg of the prostaglandin F2α (PGF2α) analogue cloprostenol (Estrumate®). The serum levels of progesterone, 20α-dihydroprogesterone (20α-DHP), prolactin (PRL) and luteinizing hormone (LH) as well as the number of ovarian LH binding sites were measured during the first 23 h after cloprostenol injection. The serum levels of progesterone decreased from 500 to 200 ng/ml within 25 min after cloprostenol administration. A further decrease to 20 ng/ml occurred during the next 4 h, and serum progesterone remained low for the rest of the period. An increase in serum prolactin (PRL) to values between 28 and 44 ng/ml was observed after 3 h and the values remained elevated for the next 7 h. Although the serum levels of progesterone declined immediately, the serum 20α-dihydroprogesterone (20α-DHP) levels remained at 60 to 140 ng/ml for the first 5 h and then gradually increased to values corresponding to the initial progesterone levels 14 to 23 h after treatment. The number of ovarian LH binding sites was between 1.2 and 1.4 × 10−12 mol/mg protein during the first 9 h after prostaglandin (PG) injection, and then decrreased to 0.8 and 0.5 × 10−12 mol/mg protein at 14 and 23 h, respectively. The serum LH levels remained below the limit of detection for the assay (10 ng/ml) throughout the observation period. PGF2α injection induced the same basic changes in the serum levels of progesterone and 20α-DHP as cloprostenol treatment. Thus, the first effect of PG treatment measured was an immediate decline in the serum levels of progesterone, and this decline probably initiated the subsequent increase in pituitay PRL and ovarian 20α-DHP secretion. Therefore, the decrease in the number of ovarian LH binding sites appeared to be a consequence rather than a mediator of luteolytic effects of the prostaglandins.

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