SERUM GONADOTROPHINS AND FOLLICULAR DEVELOPMENT IN IMMATURE RATS AFTER EARLY ANDROGEN ADMINISTRATION

1976 ◽  
Vol 68 (3) ◽  
pp. 461-468 ◽  
Author(s):  
J. TH. J. UILENBROEK ◽  
E. ARENDSEN DE WOLFF-EXALTO ◽  
M. A. BLANKENSTEIN
Keyword(s):  
Testosterone Propionate ◽  
Follicle Stimulating Hormone ◽  
Follicular Development ◽  
Female Rats ◽  
Vaginal Opening ◽  
Follicular Growth ◽  
Antral Follicles ◽  
Follicular Maturation ◽  
Immature Rats ◽  
Plasma Oestradiol

SUMMARY Follicular development and serum gonadotrophin levels were studied in female rats after neonatal androgen administration. After injection of 1250 μg testosterone propionate (TP) on day 5 after birth the composition of the follicular population was altered: at nearly all ages the number of pre-antral follicles (follicular volume 2–20 × 105 μm3) was lower than in oil-treated rats, in some cases the number of small antral follicles (21–249 × 105 μm3) was also lower. Furthermore levels of serum follicle-stimulating hormone and luteinizing hormone were decreased from day 7 to day 20 suggesting that the high gonadotrophin levels before day 20 are of importance for normal follicular development. In contrast, final follicular maturation in TP-treated rats was enhanced; at day 35 more large antral follicles (follicular volume ≥ 500 × 105μm3) were present in TP-treated rats than in oil-treated rats. The presence of more large antral follicles was accompanied by higher plasma oestradiol concentrations, higher uterine weights and advanced vaginal opening. These results demonstrate an inhibition of normal follicular growth and an acceleration of ovarian maturation after neonatal androgen administration.

scholarly journals STUDIES ON THE SIGNIFICANCE OF THE HIGH LEVELS OF FOLLICLE STIMULATING HORMONE FOR FOLLICULAR DEVELOPMENT IN IMMATURE RATS

1976 ◽  
Vol 16 (3) ◽  
pp. 297-305 ◽  
Author(s):  
J. Th. J. UILENBROEK ◽  
Els ARENDSEN de WOLFF-EXALTO ◽  
R. WELSCHEN ◽  
Lily GRIBLING-HEGGE ◽  
Mechtilda DEBETS ◽  
...  
Keyword(s):  
Follicle Stimulating Hormone ◽  
Follicular Development ◽  
Immature Rats ◽  
Stimulating Hormone

Follicular dynamics and secretion of inhibin and oestradiol-17β during the oestrous cycle of the hamster

1995 ◽  
Vol 146 (1) ◽  
pp. 169-176 ◽  
Author(s):  
H Kishi ◽  
K Taya ◽  
G Watanabe ◽  
S Sasamoto
Keyword(s):  
Plasma Levels ◽  
Marked Decrease ◽  
Plasma Concentrations ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Oestrous Cycle ◽  
Antral Follicles ◽  
Follicular Maturation ◽  
Follicular Dynamics

Abstract Plasma and ovarian levels of inhibin were determined by a radioimmunoassay (RIA) at 3-h intervals throughout the 4-day oestrous cycle of hamsters. Plasma concentrations of FSH, LH, progesterone, testosterone and oestradiol-17β were also determined by RIAs. In addition, hamsters were injected at various times with human chorionic gonadotrophin (hCG) to determine the follicular development. The changes in plasma concentrations of FSH after injection of antisera to oestradiol-17β (oestradiol-AS) and inhibin (inhibin-AS) on the morning of day 2 (day 1=day of ovulation) were also determined. Plasma concentrations of inhibin showed a marked increase on the afternoon of day 1, remained at plateau levels until the morning of day 4, then increased abruptly on the afternoon of day 4 when preovulatory LH and FSH surges were initiated. A marked decrease in plasma concentrations of inhibin occurred during the process of ovulation after the preovulatory gonadotrophin surges. An inverse relationship between plasma levels of FSH and inhibin was observed when the secondary surge of FSH was in progress during the periovulatory period. Plasma concentrations of oestradiol-17β showed three increase phases and these changes differed from those of inhibin. Changes in plasma concentrations of oestradiol-17β correlated well with the maturation and regression of large antral follicles. Follicles capable of ovulating following hCG administration were first noted at 2300 h on day 1. The number of follicles capable of ovulating reached a maximum on the morning of day 3 (24·8± 0·6), and decreased by 0500 h on day 4 (15·0 ± 1·1), corresponding to the number of normal spontaneous ovulations. Plasma concentrations of FSH were dramatically increased within 6 h after inhibin-AS, though no increase in FSH levels was observed after oestradiol-AS. These findings suggest that changes in the plasma levels of inhibin during the oestrous cycle provide a precise indicator of follicular recruitment, and that the changes in plasma concentrations of oestradiol-17β are associated with follicular maturation. These findings also suggest that inhibin may play a major role in the inhibition of FSH secretion during the oestrous cycle of the hamster. Journal of Endocrinology (1995) 146, 169–176

scholarly journals Comparative effects of testosterone propionate, oestradiol benzoate, ICI 182,780, tamoxifen and raloxifene on hypothalamic differentiation in the female rat

2002 ◽  
Vol 172 (3) ◽  
pp. 441-448 ◽  
Author(s):  
L Pinilla ◽  
ML Barreiro ◽  
LC Gonzalez ◽  
M Tena-Sempere ◽  
E Aguilar
Keyword(s):  
Positive Feedback ◽  
Testosterone Propionate ◽  
Reproductive Function ◽  
Female Rats ◽  
Normal Brain ◽  
Female Rat ◽  
Vaginal Opening ◽  
Ici 182,780 ◽  
Oestradiol Benzoate ◽  
Normal Differentiation

Hypothalamic differentiation in the female rat during the neonatal period is critically dependent on the steroid milieu, as permanent changes in reproductive function are observed after administration of oestradiol and testosterone during such a critical stage. Selective oestrogen modulators (SERMs) constitute a family of drugs that, depending on the tissue, are able to exert oestrogenic or antioestrogenic actions. The present experiments were conducted to analyse whether the SERMs, tamoxifen and raloxifene, can cause oestrogenic actions during the hypothalamic differentiation period. Postnatal female rats were injected between days 1 and 5 with 100 microg/day tamoxifen, raloxifene or ICI 182,780 (a pure antioestrogen). Other groups of animals were injected on day 1 of age with 100 microg oestradiol benzoate (OeB) or 1.25 mg testosterone propionate (TP) alone or in combination with raloxifene (500 microg/day between days 1 and 5). In all experimental groups, the age, body weight and concentrations of serum gonadotrophins at vaginal opening were recorded, whereas vaginal cyclicity and the negative and positive feedback between oestradiol and LH were monitored in adulthood. The results obtained confirmed the ability of high doses of OeB or TP to alter the normal differentiation of the brain permanently. They also reinforced the hypothesis that oestrogens are also necessary for normal brain differentiation in female rats because administration of a pure antioestrogen, such as ICI 182,780 permanently altered the function of the reproductive axis. In addition, our data provided evidence for different actions of the two SERMs under analysis (raloxifene and tamoxifen) upon peripheral targets, as raloxifene advanced vaginal opening whereas tamoxifen did not. In contrast, their actions on brain differentiation appeared similar and analogous to those obtained after neonatal administration of oestradiol, as evidenced by vaginal acyclicity, ovarian atrophy, sterility and abolition of negative and positive feedback between oestradiol and LH, thus suggesting an oestrogenic action of these SERMs on hypothalamic differentiation. Moreover, the oestrogenic activity of raloxifene was supported by its inability to block the effects of OeB and TP administered neonatally. In conclusion, the present results indicated that the SERMs, tamoxifen and raloxifene, exert an oestrogen-like effect upon hypothalamic differentiation of the neonatal female rat.

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.

Effects of systemic administration or intrabursal injection of serotonin on puberty, first ovulation and follicular development in rats

2013 ◽  
Vol 25 (8) ◽  
pp. 1105 ◽  
Author(s):  
M. J. Moran ◽  
M. E. Ayala ◽  
E. Gallegos ◽  
J. Romero ◽  
R. Chavira ◽  
...  
Keyword(s):  
Serum Concentration ◽  
Follicular Development ◽  
Systemic Administration ◽  
Female Rats ◽  
Subcutaneous Route ◽  
Vaginal Opening ◽  
Serum Concentrations ◽  
Neuroendocrine Mechanism

To elucidate the role of serotonin in the onset of puberty, the effects of both systemic and in-ovarian bursa administration of serotonin on the neuroendocrine mechanism that modulates the onset of puberty, follicular development and first ovulation were evaluated. Two experiments were carried out. For the first, 25 or 37.5 mg kg–1 of bodyweight of serotonin creatinine sulfate was administered by a subcutaneous route to 30-day-old female rats. In the second experiment, serotonin creatinine sulfate was administered directly into the ovarian bursa of 34-day-old female rats. Systemic administration of 25 or 37.5 mg kg–1 of serotonin creatinine sulfate induced a delay in the ages of vaginal opening and first vaginal oestrus, a decrease in the number of ovulating animals, and serum concentrations of FSH, LH, oestradiol and progesterone. An increase in the number of Class 3 (>500 μm) and atretic follicles was observed in the ovaries of these animals. The administration of serotonin creatinine sulfate in the ovarian bursa did not modify the onset of puberty and ovulation, but a reduced serum concentration of oestradiol was observed. Our results suggest that serotonin acts on the components of the hypothalamus–hypophysis–ovary axis by modulating follicular development, ovarian functions and the onset of puberty.

EFFECTS OF ADRENALECTOMY ON THE RELEASE OF FOLLICLE-STIMULATING HORMONE AND THE ONSET OF PUBERTY IN FEMALE RATS

1977 ◽  
Vol 75 (3) ◽  
pp. 419-426 ◽  
Author(s):  
H. M. A. MEIJS-ROELOFS ◽  
P. KRAMER
Keyword(s):  
Body Weight ◽  
Adrenal Gland ◽  
Follicle Stimulating Hormone ◽  
The Body ◽  
Biologically Active ◽  
Female Rats ◽  
Vaginal Opening ◽  
Uterine Weight ◽  
Body Weights ◽  
Adrenalectomized Rats

The involvement of the adrenal gland in the release of gonadotrophins and the onset of puberty in female rats was studied. Two and four days after adrenalectomy (ADX) on either day 5 or 10 after birth, a significant decrease in the concentration of FSH was found; 4 days after ADX on either day 15 or 20, FSH concentrations had increased significantly compared with sham-operated and/or intact controls. However, in the rats adrenalectomized on day 15 or 20, the body weights were lower than in control rats. Relative uterine weights (mg/100 g body wt) in adrenalectomized rats never differed from those of control rats. A delay in the time at which vaginal opening and the first oestrus occurred was found in rats adrenalectomized at 20 or 25 days of age; however this delay was accompanied in these rats by a retardation in the gain in body weight. It is argued that the effects of ADX on both the release of gonadotrophins and the onset of puberty are primarily, and presumably exclusively, due to the effects on general bodily development (expressed in body weight). The lack of effect of ADX on uterine weight supports the hypothesis that 'oestrogen-like' products from the adrenal gland are not biologically active as oestrogens.

scholarly journals Delayed first cycle in intrauterine growth-retarded and postnatally undernourished female rats: follicular growth and ovulation after stimulation with pregnant mare serum gonadotropin at first cycle

2002 ◽  
Vol 173 (2) ◽  
pp. 297-304 ◽  
Author(s):  
MJ Engelbregt ◽  
MM van Weissenbruch ◽  
C Popp-Snijders ◽  
HA Delemarre-van de Waal
Keyword(s):  
Body Weight ◽  
Food Restriction ◽  
Intrauterine Growth Retardation ◽  
Corpora Lutea ◽  
Vaginal Opening ◽  
Follicular Growth ◽  
Antral Follicles ◽  
Intrauterine Growth ◽  
Pregnant Mare Serum Gonadotropin ◽  
Serum Gonadotropin

In the present study we examined the consequences of intrauterine growth retardation and postnatal food restriction on the maturational process of sexual development by studying onset of first cycle. In addition, we investigated the effect of pregnant mare serum gonadotropin (PMSG) on ovarian growth and ovulation in intrauterine growth-retarded (IUGR) and postnatally food-restricted (PFR) rats. Intrauterine growth retardation was induced by uterine artery ligation on day 17 of gestation and food restriction was achieved by enlarging the litter to 20 pups per mother from day 2 after birth until weaning (day 24). In control rats, vaginal opening and the first cycle took place on the same day. In IUGR rats, uncoupling occurred between vaginal opening and the first cycle. Vaginal opening was delayed (P<0.05) and the first cycle was even further delayed (P<0.01) compared with controls. Body weight in IUGR rats was lower (P<0.05) at vaginal opening, but at first cycle and after stimulation with 50 IU PMSG in the first cycle it was similar to that in controls. In the ovaries of IUGR rats, the numbers of primordial (P<0.05), growing (P<0.01) and antral follicles (P<0.01), and the total number of follicles (P<0.01) were lower than in controls after stimulation with 50 IU PMSG at first cycle. The number of corpora lutea in the ovaries of the IUGR rats and the controls was similar and reflected superovulation. In the PFR rats, vaginal opening occurred at the same time as in control rats, but at a lower body weight (P<0.01). First cycle was much delayed (P<0.01), by which time body weight was greater (P<0.01) than that of controls at first cycle. On the basis of the differences in weight and age between PFR rats and controls at first cycle, we performed two studies. In study A, ovaries were analysed histologically 42 h after stimulation with PMSG at first cycle of control rats and age-matched PFR rats. In study B, the ovaries of PFR rats at first cycle and age-matched control rats were examined 42 h after PMSG stimulation. In the ovaries of the PFR rats in study A, a greater total number of follicles (P<0.05) was observed, represented by a greater number of primordial follicles (P<0.01) and a lower number of antral follicles (P<0.05), including corpora lutea. The number of corpora lutea in the ovaries of the PFR rats was significantly lower than that in controls (P<0.01). The total number of follicles in the ovaries of the PFR rats of study B did not differ from the age-matched controls after PMSG stimulation at first cycle, and neither did the number of the follicles in the different classes. We conclude that, in IUGR rats at first cycle, PMSG can induce multiple follicular growth and development followed by superovulation comparable to that in controls, despite a decreased total number of follicles in the ovaries. However, in PFR rats of the same age, the ovary is not capable of responding adequately to PMSG, despite a greater total number of follicles. Stimulation with PMSG at first cycle resulted in follicular growth and superovulation comparable to those in age-matched controls. Undernutrition in different critical time periods around birth in the rat leads to ovarian development in such a way that, in both groups, an increased risk of reduced reproductive capacity can be expected.

ADRENAL INVOLVEMENT IN THE TIMING OF PUBERTY IN FEMALE RATS: INTERACTION WITH SERUM PROLACTIN LEVELS

1978 ◽  
Vol 89 (3) ◽  
pp. 590-598 ◽  
Author(s):  
Marie C. Gelato ◽  
J. Meites ◽  
W. Wuttke
Keyword(s):  
Female Rats ◽  
Serum Prolactin ◽  
Vaginal Opening ◽  
Sprague Dawley ◽  
Intact Control ◽  
Immature Rats ◽  
Timing Of Puberty ◽  
Corticosterone Treatment ◽  
Adrenalectomized Rats ◽  
Intact Rats

ABSTRACT Female Sprague-Dawley derived rats were either sham-operated or adrenalectomized at 20 days of age. Treatment of separate groups of rats with progesterone, corticosterone or prolactin was started at 21 days of age, and was continued until the day of vaginal opening. Similarly treated rats were decapitated at 25, 29 and 33 days of age and at the day of vaginal opening and the sera were collected from each animal and assayed for prolactin, LH and FSH. All rats were decapitated between 4–6 p. m. Adrenalectomy, as previously reported, significantly delayed the day of vaginal opening. Prolactin treatment advanced the day of vaginal opening in intact rats and it restored the day of vaginal opening in adrenalectomized rats to that of intact control rats. Progesterone treatment always delayed the day of vaginal opening in intact rats. It caused an even greater delay in vaginal opening than adrenalectomy alone. Corticosterone treatment, on the other hand, was able to reverse the effect of adrenalectomy but had no effect on vaginal opening in intact rats. In intact rats serum prolactin levels rose steadily until the day of vaginal opening. Adrenalectomized and intact rats treated with progesterone had significantly decreased serum prolactin levels. However, in adrenalectomized corticosterone treated rats serum prolactin levels were significantly increased at all ages measured when compared to the untreated rats. The FSH and LH levels showed no significant changes during any of these experimental procedures. Approximately 50 % of the rats showed LH peaks on the day of vaginal opening as well as an increase in FSH. The data indicate a prolactin-adrenal interaction for the timing of the onset of puberty in immature rats, assuming that the day of vaginal opening in association with increased gonadotrophin levels is an indicator for the occurrence of puberty.

Ontogeny of sex differences in LH and FSH levels 48 h after castration in the rat

1981 ◽  
Vol 241 (6) ◽  
pp. E460-E464
Author(s):  
J. R. Lorenzen ◽  
J. A. Ramaley
Keyword(s):  
Follicle Stimulating Hormone ◽  
Female Rats ◽  
Hormonal Changes ◽  
Vaginal Opening ◽  
Immature Female ◽  
Immature Male ◽  
Male And Female Rats ◽  
Serum Lh ◽  
Pituitary Secretion ◽  
Serum Gonadotropin

Serum gonadotropin levels were measured 12, 24, and 48 h after gonadectomy in male and female rats (ages, 22--60 days) to assess when during development the rate of rise of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) after castration approximates that seen in the gonadectomized adult. In females serum LH levels 48 h after ovariectomy were increased above sham levels only when the ovaries were removed prior to vaginal opening. Ovariectomy on the day of vaginal opening or at older ages resulted in no increase in LH levels by 48 h after surgery. Serum FSH levels at 24 and 48 h after ovariectomy declined with increasing age at the time of ovariectomy. In males serum LH levels at 48 h after castration increased with increasing age at the time of gonadectomy. Serum FSH levels at either 12, 24, or 48 h after orchidectomy did not change appreciably with age at the time of surgery. It is concluded that the acute pituitary secretion of gonadotropins after removal of testes in the immature male resembles that seen in the mature male early in the course of the development of sexual maturity. In contrast, the acute pituitary secretion of gonadotropins after removal of the ovaries in the immature female does not resemble that seen in the ovariectomized adult until she is mature and capable of ovulating. Thus, the observed delay in the rise of LH seen in ovariectomized adults may be a function of some aspect of the hormonal changes associated with the estrous cycle.

EFFECTS OF SODIUM PENTOBARBITONE ADMINISTRATION ON GONADOTROPHIN RELEASE, FIRST OVULATION AND OVARIAN MORPHOLOGY IN PUBERTAL RATS

1976 ◽  
Vol 68 (3) ◽  
pp. 431-437 ◽  
Author(s):  
P. OSMAN ◽  
H. M. A. MEIJS-ROELOFS
Keyword(s):  
Oocyte Maturation ◽  
Cumulus Cells ◽  
Female Rats ◽  
Corpora Lutea ◽  
Follicular Growth ◽  
Adult Rats ◽  
Antral Follicles ◽  
Ovarian Morphology ◽  
Ovulatory Process

SUMMARY Pubertal female rats received sodium pentobarbitone (PB; 45 mg/kg body wt) at various hours on the day of first pro-oestrus. Maximal blockade of ovulation, in about 60% of the rats, occurred after PB treatment at 12.00, 13.00 and 14.00 h. The number of small antral follicles (100–499 × 105 μm3) was reduced 1 day after PB treatment in both blocked and ovulating rats. In the ovaries of non-ovulating rats signs of stimulation by LH such as dispersion of cumulus cells, oocyte maturation and early luteinization were sometimes present; in ovulating rats cystic corpora lutea with entrapped ova were found in addition to normal corpora lutea. Gonadotrophin measurements after PB treatment (14.00 h) in pubertal and adult rats showed (at 17.00 h) reduced levels of both LH and FSH, these levels being lower in the adults. Gonadotrophin levels of blocked and ovulating pubertal rats overlapped. In PB-treated, pubertal rats in which ovulation was postponed by 1 day, vaginal oestrus was prolonged by 1 day and the subsequent dioestrus by 2 days. The pubertal rat is thus less sensitive to PB treatment than the adult. PB treatment of the younger animal influences not only the ovulatory process but also follicular growth and, presumably, the length of the approaching cycle.

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