PLASMA PROGESTERONE AND ITS RELATIONSHIP TO SERUM GONADOTROPHINS IN IMMATURE FEMALE RATS

1975 ◽  
Vol 64 (2) ◽  
pp. 329-336 ◽  
Author(s):  
H. M. A. MEIJS-ROELOFS ◽  
W. J. DE GREEF ◽  
J.TH.J. UILENBROEK
Keyword(s):  
Body Weight ◽  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Female Rats ◽  
Immature Female ◽  
Plasma Progesterone ◽  
Adult Rat ◽  
Progesterone Treatment ◽  
Serum Luteinizing Hormone ◽  
Oestradiol Benzoate

SUMMARY In immature female rats, low values for concentrations of plasma progesterone were generally found from days 6–15 and from days 25–32 of life. Maximum progesterone concentrations (13·0–14·1 ng/ml), comparable to metoestrous values in the adult rat, occurred on days 20–22. The progesterone appeared to be of ovarian origin since after ovariectomy, on day 18, low progesterone concentrations were found 1 and 2 days later (2·5 ng/ml and 1·3 ng/ml) as compared with control values of 10·7 ng/ml and 14·1 ng/ml. However, adrenalectomy also lowered progesterone concentrations, 1 and 2 days later (6·4 and 4·9 ng/ml). The effect of progesterone, either alone or in combination with oestradiol benzoate (OB), on serum gonadotrophins was studied in rats ovariectomized on day 18. The highest dose of progesterone (0·15 mg) only slightly diminished the rise in serum luteinizing hormone (LH) after ovariectomy and had no effect on serum follicle-stimulating hormone (FSH). Oestradiol benzoate in a dose of 0·025 μg/100 g body weight was highly effective in preventing the rise in both LH and FSH concentrations, and OB treatment (resulting in a near-physiological oestradiol concentration) combined with progesterone treatment was more effective than treatment with OB alone. The results suggest that the amounts of progesterone and oestradiol present in the 20-day-old rat are adequate to cause the decrease in FSH level normally observed in immature female rats around this age.

SERUM LUTEINIZING HORMONE AND FOLLICLE-STIMULATING HORMONE CONCENTRATIONS IN IMMATURE FEMALE RATS TREATED WITH MULTIPLE INJECTIONS AND VARIOUS AMOUNTS OF LUTEINIZING HORMONE RELEASING HORMONE

1975 ◽  
Vol 66 (1) ◽  
pp. 13-20 ◽  
Author(s):  
D. C. JOHNSON ◽  
R. S. MALLAMPATI
Keyword(s):  
Luteinizing Hormone ◽  
Constant Stimulus ◽  
Female Rats ◽  
Intact Female ◽  
Immature Female ◽  
Luteinizing Hormone Releasing Hormone ◽  
Releasing Hormone ◽  
Serum Luteinizing Hormone ◽  
Serum Lh ◽  
Lh Rh

SUMMARY Release of immunoreactive LH and FSH was induced in immature intact female rats by repeated injections of synthetic luteinizing hormone releasing hormone (LH-RH). Altering the dose of LH-RH (5, 10, 20, 50 ng) and the frequency of administration (every 10, 20, 30 or 60 min) over a period of 2 h produced a variety of serum LH and FSH concentrations and ratios. When the dose was a constant 20 ng but the frequency of injections was either 20 or 30 min, a steady state in serum gonadotrophin concentrations was reached within 1 h and the level remained the same during the second hour. When given every 10 min, 20 ng LH-RH produced a much higher concentration of both LH and FSH during the second hour of stimulation. Examination of the gonadotrophin levels after each injection of LH-RH showed that the pituitary response was variable in spite of a constant stimulus.

THE EFFECT OF PINEAL METHOXYINDOLES ON RAT VAGINAL OPENING TIME

1971 ◽  
Vol 50 (4) ◽  
pp. 679-683 ◽  
Author(s):  
R. COLLU ◽  
F. FRASCHINI ◽  
L. MARTINI
Keyword(s):  
Luteinizing Hormone ◽  
Sexual Maturation ◽  
Lateral Ventricle ◽  
Follicle Stimulating Hormone ◽  
Female Rats ◽  
Vaginal Opening ◽  
Significant Delay ◽  
Immature Female ◽  
The Brain ◽  
Stimulating Hormone

SUMMARY Melatonin and 5-methoxytryptophol, the two methoxyindoles of pineal origin, were injected into a lateral ventricle of the brain of immature female rats. Treatment was started on the 25th day of age and terminated when the vagina opened. The injection of both methoxyindoles resulted in a statistically significant delay in vaginal opening. Since previous experiments had shown that melatonin specifically inhibits secretion of luteinizing hormone and that 5-methoxytryptophol specifically blocks release of follicle-stimulating hormone, the present results support the hypothesis that the onset of sexual maturation needs a balanced secretion of both gonadotrophins.

scholarly journals Comparison of inhibitory effect of ibuprofen with Piper guineense Schumach and Thonn. on some reproductive hormones in female rats

2017 ◽  
Vol 6 (4) ◽  
pp. 205-209
Author(s):  
Emmanuel Onuka Agbai ◽  
◽  
Chisomaga Chiwuikem Eke ◽  
Collins Okechukwu Nwanegwo ◽  
Ugochukwu Bond Anyaehie ◽  
...  
Keyword(s):  
Luteinizing Hormone ◽  
Follicle Stimulating Hormone ◽  
Inhibitory Effect ◽  
Female Rats ◽  
Assay Method ◽  
Piper Guineense ◽  
Serum Luteinizing Hormone ◽  
Group B ◽  
Group D ◽  
Stimulating Hormone

The aim of the present study was to compare the inhibitory effect of ibuprofen with oral administration of Piper guineense leaf extract on follicle-stimulating hormone, luteinizing hormone, progesterone and estrogen in female rats irrespective of the estrous cycle. The animals were randomly assigned to four groups (n = 7): group A (control), Group B, 180 mg-kg of ibuprofen, Group C, 200 mg-kg of Piper guineense extract, Group D, 180 mg-kg of ibuprofen and 200 mg-kg of Piper guineense extract. At the end of two weeks administration, rats were sacrificed under urethane anesthesia and hormones measured using enzyme-linked immunosorbent assay method. Results showed significant reduction in serum follicle-stimulating hormone and luteinizing hormone following ibuprofen administration in Group B rats at P < 0.05. Piper guineense extract treated Group C rats caused significant reduction in serum luteinizing hormone and progesterone at P < 0.05. In contrast, serum follicle stimulating hormone significantly increased in Group D rats at P < 0.05 whereas serum luteinizing hormone and progesterone were markedly reduced at P < 0.05. Serum estrogen level remained unchanged among groups. In conclusion, results obtained suggested that extract inhibited luteinization of follicles thus could impair ovulation, therefore the extract can be used as oral contraceptive in family planning.

β-Endorphin and dynorphin control serum luteinizing hormone level in immature female rats

Nature ◽  
1981 ◽  
Vol 294 (5843) ◽  
pp. 757-759 ◽  
Author(s):  
Rüdiger Schulz ◽  
Annemarie Wilhelm ◽  
Karl Martin Pirke ◽  
Christian Gramsch ◽  
Albert Herz
Keyword(s):  
Luteinizing Hormone ◽  
Hormone Level ◽  
Female Rats ◽  
Luteinizing Hormone Level ◽  
Immature Female ◽  
Serum Luteinizing Hormone ◽  
Control Serum ◽  
Serum Luteinizing Hormone Level

INFLUENCE OF AGE ON THE RELEASE OF LUTEINIZING HORMONE INDUCED BY OESTROGEN AND PROGESTERONE IN IMMATURE RATS

1972 ◽  
Vol 55 (1) ◽  
pp. 97-103 ◽  
Author(s):  
L. CALIGARIS ◽  
J. J. ASTRADA ◽  
S. TALEISNIK
Keyword(s):  
Luteinizing Hormone ◽  
Single Injection ◽  
Significant Rise ◽  
Female Rats ◽  
Serum Luteinizing Hormone ◽  
Serum Lh ◽  
Oestradiol Benzoate ◽  
Old Rats ◽  
Lh Secretion ◽  
Phasic Release

SUMMARY In immature female rats serum luteinizing hormone (LH) concentration, as measured by radioimmunoassay, was found to be higher at 10 or 15 days of age than thereafter. Animals ovariectomized soon after birth or at 5 days of age showed a significant rise in serum LH levels 10 days later. A positive feedback effect on LH secretion was observed on the day following a single injection of oestradiol benzoate (OB) in 28-day-old rats but not in younger animals. However, in animals primed with OB a second dose of OB 2 days later resulted in a significant rise in serum LH levels even in rats of 22 days of age. Progesterone (1 mg) injected 3 days after the injection of a single dose of OB induced, a few hours later, a significant rise in serum LH concentration. This effect was observed from the 22nd day of age but not in younger animals. The magnitude of the response to progesterone, as revealed by the serum LH levels, sharply decreased at the time of puberty. It is concluded that the mechanisms responsible for the tonic release of LH are ready to function at the time of birth or shortly thereafter, while those involved in the phasic release mature around 22 days of age.

INCREASED PRODUCTION OF FOLLICLE-STIMULATING HORMONE IN IMMATURE FEMALE RATS BY A SINGLE INJECTION OF ANDROGEN OR OESTROGEN

1969 ◽  
Vol 45 (1) ◽  
pp. 29-36 ◽  
Author(s):  
R. H. NAQVI ◽  
D. C. JOHNSON
Keyword(s):  
Testosterone Propionate ◽  
Single Injection ◽  
Follicle Stimulating Hormone ◽  
Ovarian Response ◽  
Steroid Treatment ◽  
Female Rats ◽  
Immature Female ◽  
Ovarian Weight ◽  
Oestradiol Benzoate ◽  
Stimulating Hormone

SUMMARY An increase in ovarian weight in immature rats after the injection of chorionic gonadotrophin (HCG) was used to measure variations in endogenous follicle-stimulating hormone (FSH) after steroid treatment. A single injection of several steroids (testosterone, androstenediol, androstenedione, oestradiol benzoate) given 12–96 hr. before treatment with HCG caused a 30–200% increase in ovarian weight. This was not a direct effect of the steroids since hypophysectomy abolished the response, and administration of the compounds concurrently with HCG was ineffective. Within certain limits an increase in the duration of pretreatment enhanced the ovarian response while an increase in the dose of steroid had little effect. Pretreatment with testosterone propionate did not change pituitary FSH activity, indicating that the increase in circulating FSH was due to an increased production of hormone. On the other hand, pituitary FSH in animals treated with oestradiol benzoate was significantly lowered within 72 hr. suggesting an increased release of FSH.

SERUM AND PITUITARY LUTEINIZING HORMONE, FOLLICLE-STIMULATING HORMONE AND PROLACTIN LEVELS IN GONADECTOMIZED MALE, FEMALE AND ANDROGENIZED FEMALE RATS TREATED WITH OESTRADIOL BENZOATE

1973 ◽  
Vol 59 (2) ◽  
pp. 209-216 ◽  
Author(s):  
R. S. MALLAMPATI ◽  
D. C. JOHNSON
Keyword(s):  
Luteinizing Hormone ◽  
Post Partum ◽  
Follicle Stimulating Hormone ◽  
Female Rats ◽  
Serum Prolactin ◽  
Normal Female ◽  
Male And Female Rats ◽  
Oestradiol Benzoate ◽  
Prolactin Content ◽  
Stimulating Hormone

SUMMARY Changes in serum concentrations and pituitary content of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and prolactin, determined by radioimmunoassay, were studied after oestradiol benzoate (OEB) administration to gonadectomized male and female rats and to gonadectomized females androgenized with 50 μg testosterone propionate on the 5th day post-partum. Oestradiol benzoate (0·05–50 μg) was given once a day for 7 days beginning 3 weeks after removal of the gonads. A rise in serum LH concentration was produced by 0·05 μg OEB in all animals, but a reduction was found with the larger doses. Serum FSH increased in females injected with 0·05 μg OEB, but males and androgenized females had decreased FSH levels with all doses. The prolactin concentrations increased in the sera of all animals treated with 0·05 μg or 0·5 μg oestrogen. Males showed no further increases with larger doses. A very large increase was found in females given 5 μg but 50 μg did not have this stimulatory effect. Dose-dependent increases in serum prolactin were noted in androgenized females. Pituitary prolactin content increased in females and androgenized females treated with oestrogen; a slight, but significant, increase was found only in the males given 50 μg. Pituitary LH was increased only in the animals receiving a large amount of oestrogen (5 or 50 μg). Glandular FSH increased in the males and androgenized females given 0·5 μg OEB, but in all animals a reduction in this gonadotrophin was found after giving 50 μg of the oestrogen. The results indicate that androgenization alters the normal female hypothalamo-hypophysial response to oestrogen but it does not induce the response pattern of the male.

PLASMA OESTRADIOL-17β AND ITS RELATIONSHIP TO SERUM FOLLICLE-STIMULATING HORMONE IN IMMATURE FEMALE RATS

1973 ◽  
Vol 59 (2) ◽  
pp. 295-304 ◽  
Author(s):  
H. M. A. MEIJS-ROELOFS ◽  
J. Th. J. UILENBROEK ◽  
F. H. de JONG ◽  
R. WELSCHEN
Keyword(s):  
Similar Pattern ◽  
Follicle Stimulating Hormone ◽  
Serum Levels ◽  
Feedback Mechanism ◽  
Female Rats ◽  
Immature Female ◽  
Oestradiol Benzoate ◽  
Steep Decrease ◽  
Level 2 ◽  
Stimulating Hormone

SUMMARY Oestradiol-17β (E2) was measured by radioimmunoassay in the plasma of immature female rats. Maximal E2 levels of 55–60 pg/ml were found at 10–15 days of age; from day 25 to day 35 E2 levels were low to undetectable. The E2 measured appeared to be of ovarian origin: ovariectomy performed on day 13 resulted in a decreased E2 level 2 days later (13 pg/ml) as compared with the value from the control litter mates (46 pg/ml); after adrenalectomy the level of circulating E2 remained normal (54 pg/ml). The effects of ovariectomy and adrenalectomy on uterine weights followed a similar pattern: ovariectomy resulted in a decrease and adrenalectomy in no change in uterine weight. In the strain of rat used, levels of follicle-stimulating hormone (FSH) in the serum (measured by radioimmunoassay) were high from day 10 to day 20 and showed a steep decrease on day 21. After ovariectomy on day 15 this decrease in serum FSH was not observed. The influence of circulating E2 on serum levels of FSH was studied after ovariectomy followed by treatment with varying doses of oestradiol benzoate. Ovariectomy on day 13 resulted in a significantly increased FSH level 2 days later (1770 ng NIAMD-rat-FSH RP-1/ml) as compared with the value obtained from control animals (1033 ng/ml). This increase was not observed after daily injections of 0·1 μg oestradiol benzoate/100 g body weight. The results indicate that E2 and FSH concentrations show a similar pattern between 5 and 35 days of age. Furthermore, an inhibitory feedback mechanism between oestrogens and FSH concentrations was found to be operative. The implications of these findings are discussed.

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