THE EFFECT OF A SINGLE INJECTION OF DIETHYLSTILBOESTROL OR PROGESTERONE ON THE HAMSTER OVARY

1965 ◽  
Vol 33 (1) ◽  
pp. 13-23 ◽  
Author(s):  
G. S. GREENWALD
Keyword(s):  
Anterior Pituitary ◽  
Single Injection ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Oestrous Cycle ◽  
The Other ◽  
Follicular Atresia ◽  
Follicular Growth ◽  
Antral Follicles

SUMMARY A single injection of 0·25 mg. stilboestrol or 5 mg. progesterone at metoestrus (day 1) affected follicular development in the hamster ovary in different ways. Stilboestrol induced widespread follicular atresia but apparently did not interfere with the release of ovulating hormone at the end of the oestrous cycle. The atresia produced by stilboestrol appears to be mediated by changes in the levels of circulating gonadotrophin rather than by a direct effect on the ovary. This was demonstrated by injecting pregnant mare serum on day 1 of the cycle followed by stilboestrol treatment at various times thereafter. Under these circumstances the ovulation rate was only reduced below control values when stilboestrol was injected on day 1. Progesterone given on day 1 of the cycle did not interfere with the maturation of healthy Graafian follicles but acted on the terminal stages of follicular growth by blocking ovulation. After a single injection of progesterone, the life span of antral follicles was prolonged to 8–9 days. The ovulation-inhibiting effects of progesterone given on day 1 of the cycle were overcome by the injection of human chorionic gonadotrophin on day 4. Thus, progesterone blocked ovulation indirectly by preventing release of ovulating hormone from the anterior pituitary. The effects of shifting the single injection of stilboestrol or progesterone to the other days of the oestrous cycle are also considered.

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

FOLLICULAR DEVELOPMENT IN THE ADULT GUINEA-PIG AND RESPONSES TO HUMAN CHORIONIC GONADOTROPHIN

1980 ◽  
Vol 85 (1) ◽  
pp. 9-16 ◽  
Author(s):  
M. J. PEDDIE
Keyword(s):  
Luteal Phase ◽  
Continuous Process ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Follicular Growth ◽  
Antral Follicles ◽  
Late Luteal Phase ◽  
Cycle Lengths ◽  
Two Stages

SUMMARY The development of antral follicles and of atretic follicles throughout the cycle of adult guinea-pigs is a continuous process, but there are two stages when atresia is most pronounced: immediately after oestrus and in the late luteal phase. New atretic antral follicles were not found in the ovaries until around day 10 of the cycle, when an injection of HCG caused atresia of the medium-sized antral follicles within the ovary and luteinization of the largest follicles but spared the smallest antral follicles. Following the induced atresia, cycle lengths were prolonged, but the population of antral follicles could be restored to normal within 10 days of gonadotrophin treatment. It is suggested that the growth rate of antral follicles is flexible and proceeds most rapidly at the end of the luteal phase. It is not clear whether ovarian steroids play an integral part in regulating follicular growth and atresia.

AUGMENTATION BY CHLORMADINONE OF THE UTERINE WEIGHT RESPONSE TO HUMAN CHORIONIC GONADOTROPHIN IN INTACT IMMATURE RATS

1965 ◽  
Vol 33 (3) ◽  
pp. 447-454
Author(s):  
M. J. K. HARPER
Keyword(s):  
Single Injection ◽  
Direct Action ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Female Rats ◽  
Uterine Weight ◽  
Control Value ◽  
Orally Active ◽  
Stimulation Of

SUMMARY Administration of chlormadinone, an orally active progestational agent without significant oestrogenic activity, to intact immature female rats did not affect either ovarian or uterine weight significantly compared with controls. A single injection of human chorionic gonadotrophin (HCG) caused a 73 % increase in uterine weight in 24 hr. over the control value. This dose significantly increased ovarian weight and although it caused some stimulation of follicular development, ovulation during this time did not occur. When animals were treated with chlormadinone for 8 days, and received HCG on the 8th day, uterine weight was 170% greater than in the controls and 56% greater than with HCG alone. The uterine weight produced was similar to that found in animals treated with mestranol, a potent oestrogen, and HCG. In ovariectomized animals HCG did not affect uterine weight, while the small increase produced by chlormadinone was unaltered when HCG also was given. Mechanisms are discussed by which this augmentation of the uterine response to HCG might be produced. It seems most likely that chlormadinone administration causes storage of endogenous gonadotrophin in the pituitary, and that the exogenous gonadotrophin acts as the 'trigger' for the release of stored hormone, probably by a direct action on the hypothalamus.

INITIATION OF FOLLICULAR MATURATION AND OVULATION AFTER REMOVAL OF THE LITTER FROM THE LACTATING RAT

1980 ◽  
Vol 87 (3) ◽  
pp. 393-400 ◽  
Author(s):  
KAZUYOSHI TAYA ◽  
SHUJI SASAMOTO
Keyword(s):  
Plasma Levels ◽  
Plasma Concentrations ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Moderate Increase ◽  
Normal Cycle ◽  
Antral Follicles ◽  
Follicular Maturation ◽  
Follicular Activity

In order to elucidate the mechanism of the resumption of follicular activity and ovulation in rats, levels of FSH, LH and prolactin in plasma and pituitary gland and ovarian follicular development were quantified after removal of the litter on day 3 of lactation (day of parturition = day 0 of lactation). Such removal resulted in ovulation of 13 oocytes 4 days later, a number comparable with that found in normal cyclic rats. Plasma levels of prolactin were high during lactation but markedly decreased after removal of the litter. Although plasma concentrations of FSH and LH did not change during days 3–7 of lactation, there was an FSH surge between 24 and 30 h after removal of the litter. Plasma concentrations of LH also increased slightly but significantly by 24 h after removal of the litter and this value persisted during the following 2 days. Surges of FSH, LH and prolactin occurred at 17.00 h 3 days after pups were removed. Removal of the litter did not increase pituitary contents of FSH, LH and prolactin and a marked reduction in pituitary levels of FSH and LH, but not of prolactin, occurred at 17 00 h 3 days after removal of the litter. A quantitative study of follicular development indicated that follicles larger than 401 μm in diameter were absent during days 3–7 of lactation. However, the number and size of antral follicles increased by 30 h after removal of the litter, probably due to the increases in plasma levels of FSH and LH, and follicles larger than 601 μm in diameter appeared 3 days after the young were removed. Although ovulation could not be induced by human chorionic gonadotrophin from days 3 to 5 of lactation, its administration 30 h after removal of the litter produced ovulation in all rats by the following morning. These results indicated that a moderate increase in FSH, although below the amounts released at the preovulatory surge, together with basal levels of LH which were within the range observed on the day of dioestrus during the normal cycle were responsible for the initiation of follicular maturation after removal of the litter.

scholarly journals The effect of H-2 region and genetic background on hormone-induced ovulation rate, puberty, and follicular number in mice

1991 ◽  
Vol 57 (1) ◽  
pp. 41-49 ◽  
Author(s):  
J. L. Spearow ◽  
R. P. Erickson ◽  
T. Edwards ◽  
L. Herbon
Keyword(s):  
Genetic Background ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Ovulation Rate ◽  
Follicular Atresia ◽  
Linked Gene ◽  
Induced Ovulation ◽  
Follicular Maturation ◽  
Timing Of Puberty

SummaryWe have examined the effects of major histocompatibility (H-2) haplotypes and genetic background (all loci other than the H-2 region) on hormone-induced ovulation rate in congenic strains of mice. In comparison with the H-2a haplotype, the H-2b haplotype increased hormone-induced ovulation rate 92% on the A/J (A) genetic background. However, H-2 haplotype did not affect hormone-induced ovulation rate on the C57BL/10J (C57) genetic background. The H-2b-linked gene(s) increased hormone-induced ovulation rate on the A/J genetic background largely by (1) enhancing the maturation of follicles in response to pregnant mare's serum gonadotrophin (PMSG) and (2) altering the stages of follicular development which can be induced to ovulate in response to human chorionic gonadotrophin (hCG). The observed effects of H-2 on hormone-induced ovulation rate were not explained by differences in the timing of puberty, the number of follicles present in untreated females, or the incidence of follicular atresia. The effect of genetic background on hormone-induced ovulation rate was much greater than was the effect of the H-2 region. We found that hormone-induced ovulation rate was five- to six-fold higher on the C57 genetic background than on the A genetic background. The C57 genetic background increased hormone-induced ovulation rate by (1) enhancing the induction of follicular maturation in response to gonadotropins and (2) by reducing the incidence of follicular atresia.

EFFECTS OF CONTINUOUS LIGHT ON THE REPRODUCTIVE CYCLE OF THE FEMALE RAT: INDUCTION OF OVULATION AND PITUITARY GONADOTROPHINS DURING PERSISTENT OESTRUS

1967 ◽  
Vol 38 (4) ◽  
pp. 389-394 ◽  
Author(s):  
K. B. SINGH ◽  
G. S. GREENWALD
Keyword(s):  
Luteinizing Hormone ◽  
Single Injection ◽  
Follicle Stimulating Hormone ◽  
Continuous Light ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
The Other ◽  
Constant Light ◽  
Female Rat ◽  
Control Light

SUMMARY The majority of rats exposed to constant light for approximately 6 weeks ovulated within 24 hr. after an injection of human chorionic gonadotrophin (HCG), but required 24–48 hr. after a single injection of progesterone. This suggests that HCG acted directly on the ovary but that progesterone acted indirectly by way of the hypothalamo-hypophysial system. Animals injected with progesterone after 6 weeks of constant light failed to ovulate after single or spaced injections of progesterone at 90 days of constant light while HCG administration was still effective. Pituitary content and concentration of luteinizing hormone (LH) in constant-light animals (duration of constant light: 45 days) were below normal pituitary levels during prooestrus and were in the range of normal oestrous values. On the other hand, follicle-stimulating hormone (FSH) content and concentration were similar to those in cyclic rats. Single injections of 1 mg. progesterone changed neither LH nor FSH concentration, despite the fact that such treatment induced ovulation. Bilateral ovariectomy increased both LH and FSH content and concentration in constant-light animals to the same extent as in control light—dark animals.

EFFECT OF OESTROGEN AND PROGESTERONE ON PITUITARY GONADOTROPHIC CONTENT OF THE CYCLIC HAMSTER

1967 ◽  
Vol 56 (2) ◽  
pp. 244-254 ◽  
Author(s):  
James E. Keever ◽  
Gilbert S. Greenwald
Keyword(s):  
Follicular Development ◽  
Mature Female ◽  
Oestrous Cycle ◽  
The Other ◽  
Normal Pattern ◽  
Concurrent Administration ◽  
Female Hamster ◽  
Antral Follicles ◽  
Other Hand

ABSTRACT Oestradiol cyclopentylpropionate (ECP) and progesterone alter the normal pattern of LH synthesis and release in the mature female hamster. Both compounds also inhibit ovulation, but through different mechanisms. A dose of 50 μg ECP, injected s. c. on day 1 of the oestrous cycle, causes atresia of all vesicular follicles within 48 hours. This is related temporally to a decrease in pituitary LH content. On the other hand, 5 mg progesterone, administered at day 1, does not change the normal pattern of follicular development, but inhibits ovulation by preventing the ovulatory surge of LH on day 4. The number of healthy antral follicles is halved between days 3 and 4 of the oestrous cycle in untreated controls and animals given 5 mg progesterone on day 1. This coincides with a decrease in pituitary FSH content of both groups. Animals administered 50 μg ECP on day 1 show no decrease in pituitary FSH between days 3 and 4. Concurrent administration of 50 μg ECP and 5 mg progesterone on day 1 inhibits both synthesis and release of LH, as evidenced by a decreased pituitary content and atrophic ovaries. The present study indicates that ECP causes atresia indirectly via a decrease in LH synthesis and release during the first two days of the oestrous cycle. Progesterone, however, does not alter the normal pattern of follicular development or pituitary LH content until day 4, at which time the release of LH is blocked.

INDUCTION OF SUPEROVULATION AND PREGNANCY IN MATURE MICE BY GONADOTROPHINS

1957 ◽  
Vol 15 (4) ◽  
pp. 374-384 ◽  
Author(s):  
RUTH E. FOWLER ◽  
R. G. EDWARDS
Keyword(s):  
Litter Size ◽  
Mature Female ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Oestrous Cycle ◽  
The Other ◽  
Female Mice ◽  
Irregular Distribution ◽  
Natural Mating

SUMMARY 1. The injection of 1 i.u. pregnant mares' serum (PMS) followed after 40 hr by 2 i.u. human chorionic gonadotrophin (HCG), or of 3 i.u. PMS followed by 3 i.u. HCG into mature female mice selected at random with regard to their oestrous cycle induces oestrus and mating in approximately 75%, and ovulation in 99% of them. 2. The induction of superovulation depends on the amount of PMS injected and on the strain of mice used. 3. Two types of egg are ovulated, one being normal and with a cumulus, the other degenerated and without cumulus. 93% of the normal eggs were fertilized and 98% of the pronucleate eggs possessed two pronuclei. 4. Approximately three-quarters of the females which mate in response to the injected gonadotrophins become pregnant, although this number was less than the number becoming pregnant after mating during natural oestrus. Many of the treated females carried their embryos to term and some gave birth to large litters, although resorptions, irregular distribution of embryos in the uterus, and difficulty during parturition occurred in some females. Mean litter size of the treated females was similar to that found after natural mating. 5. After more than one treatment with gonadotrophins, fewer females mated, ovulated, and became pregnant than after the first treatment. This reduction in response may have been due to the greater age of the females or to their decreased sensitivity to the hormones. 6. The value of the method as a technique for inducing oestrus, ovulation, and pregnancy in mature female mice is considered.

INDUCTION OF OVULATION BY GONADOTROPHINS IN THE INDIAN FIVE-STRIPED PALM SQUIRREL FUNAMBULUS PENNANTI (WROUGHTON)

1967 ◽  
Vol 39 (3) ◽  
pp. 369-NP ◽  
Author(s):  
PUSHPA SETH ◽  
M. R. N. PRASAD
Keyword(s):  
Breeding Season ◽  
Reproductive Cycle ◽  
Single Injection ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Follicular Growth ◽  
Induction Of Ovulation ◽  
Induced Ovulation ◽  
Follicular Maturation ◽  
Pregnant Mare Serum Gonadotrophin

SUMMARY Superovulation was induced in palm squirrels by the administration of gonadotrophins. The regimen of treatment effective in inducing ovulation was 60 i.u. pregnant mare serum gonadotrophin (PMS) administered in three doses of 20 i.u. on days 1, 4 and 7, followed by a single injection of 40 i.u. human chorionic gonadotrophin (HCG) on day 14. The same schedule of PMS and HCG administration induced ovulation in mature and immature squirrels both during the breeding season and the period of sexual quiescence. Ovulation did not occur in PMS-treated females if HCG was not administered. The period required for follicular growth before the follicles responded to the ovulatory stimulus of HCG was 13–14 days; the interval for follicular maturation leading to the release of the ovum was approximately 24 hr. Variations in the numbers of ova shed by different groups of females are related to the phase of the reproductive cycle and the age of the squirrels.

Luteinizing hormone increases the number of ova shed in the cyclic hamster and guinea-pig

1984 ◽  
Vol 101 (3) ◽  
pp. 289-298 ◽  
Author(s):  
F. Garza ◽  
M. A. Shaban ◽  
P. F. Terranova
Keyword(s):  
Guinea Pig ◽  
Binding Sites ◽  
Follicular Development ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Serum Concentrations ◽  
Sustained Development ◽  
Antral Follicles ◽  
Preovulatory Follicles ◽  
Pregnant Mare Serum Gonadotrophin

ABSTRACT Osmotic minipumps containing 400 μg ovine LH installed subcutaneously on day 1 (oestrus) of the cycle in the hamster induced superovulation of 30·0 ± 2·1 ova (n=5) at the next expected oestrus. Controls ovulated 12·0 ± 0·8 ova (n = 6). Bovine LH, human LH, porcine LH, human chorionic gonadotrophin and pregnant mare serum gonadotrophin were effective in approximately doubling the number of ova spontaneously shed in the hamster. Ovine FSH (200 μg/pump) was most effective in increasing the number of ova spontaneously shed (55 ± 6, n=5) in the hamster. Infusion of ovine LH on days 1–4 prevented the reduction of the number of antral follicles that occurs normally between days 3 and 4 of the 4-day cycle. Since this reduction in follicular numbers in control cyclic hamsters is due to atresia, the exogenous LH might prevent atresia of the developing follicles. In the hamster, exogenous ovine LH significantly increased the serum concentrations of androstenedione, oestradiol and LH but not of FSH. Hamsters were hypophysectomized on the day of oestrus, given immediate LH (400 pg) or FSH (200 μg) replacement therapy and autopsied on day 4. Ovarian histology revealed that immediate LH treatment after hypophysectomy sustained development of histologically normal preovulatory follicles but had no effect on the number of smaller sizes of follicles. Immediate FSH treatment after hypophysectomy increased only the number of smaller sized follicles. Since LH did not increase the smaller sized follicles, no 'FSH-like' effect on follicular development was observed. In the hamster, the ability of various preparations of LH to induce superovulation did not correlate with their ability to displace 125I-labelled ovine FSH from its ovarian binding sites. The superovulatory action of LH required the presence of the pituitary gland, indicating that LH might synergize with FSH and/or prolactin (or hamster LH) for spontaneous superovulation and it appears that exogenous LH might induce superovulation by prevention of atresia. Infusion of LH into the guinea-pig beginning on day 12 of the cycle (day 1 is the day of ovulation) doubled the ovulation rate whereas in the cyclic rat and mouse LH treatment throughout the cycle was ineffective in increasing the number of ova shed. J. Endocr. (1984) 101, 289–298

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