scholarly journals Ovulation Rate and Inhibin Levels in Gonadotrophin-treated Mice

1985 ◽  
Vol 38 (1) ◽  
pp. 115 ◽  
Author(s):  
Victor WK Lee ◽  
William RGibson
Keyword(s):  
Circulatory System ◽  
Ovarian Follicles ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Follicular Growth ◽  
Immature Female ◽  
Positive Correlation ◽  
Female Mice ◽  
Ovarian Follicular Growth

Ovarian follicular growth was induced in immature female mice with varying doses of pregnant mare's serum gonadotrophin. The numbers of ovulations were determined either by counting tubal oocytes or corpora lutea in the ovary. Ovarian and circulatory levels of inhibin rose progressively with increasing doses of PMSG and a positive correlation (P < O� 0 I) was found between circulating inhibin levels and ovulation rate. The latter correlation makes it likely that the growing preovulatory ovarian follicles are the predominant source for the secretion of inhibin into the circulatory system.

IDENTIFICATION OF OVARIAN FOLLICLES AT ESTRUS AND DEVELOPMENT OF THEIR ENSUING CORPORA LUTEA IN SINGLE AND MULTIPLE OVULATING EWES ON TWO FEEDING REGIMES

1977 ◽  
Vol 57 (4) ◽  
pp. 647-652 ◽  
Author(s):  
J. J. DUFOUR ◽  
P. MATTON
Keyword(s):  
High Energy ◽  
Ovarian Follicles ◽  
Low Energy ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
The Third ◽  
India Ink ◽  
Feeding Regimes

Twelve hours after standing estrus was first detected, 30 ewes had their four largest follicles identified and marked with India ink. Seven days later, ovulation rates and origin of the corpora lutea (CL) from previously marked follicles were determined. Feeding a high energy ration from day 10 to estrus did not change the ovulation rate as compared to feeding a low energy ration. Its only effect was to increase the diameter of the third and fourth largest follicles. The diameter of the largest follicle was identical in single and multiple ovulators. However, in multiple ovulators, the diameter of the second largest follicle was larger than in single ovulators. The largest follicle identified at estrus developed into a CL that was 15% heavier in single than in multiple ovulators. In multiple ovulators, the second largest follicle developed into a CL of weight similar to that from the largest follicle.

Initial ovulation rate and follicle population after injection of inhibin-neutralizing antiserum in the late-prepubertal rat

1991 ◽  
Vol 130 (2) ◽  
pp. 289-296 ◽  
Author(s):  
H. J. Sander ◽  
H. M. A. Meijs-Roelofs ◽  
E. C. M. van Leeuwen ◽  
P. Kramer ◽  
W. A. van Cappellen
Keyword(s):  
Neutralizing Antibodies ◽  
Ovulation Rate ◽  
Female Rats ◽  
Corpora Lutea ◽  
Female Rat ◽  
Follicle Growth ◽  
Immune Control ◽  
Immature Female ◽  
Antral Follicles ◽  
Control Serum

ABSTRACT In late-prepubertal female rats passive immunoneutralization of endogenous inhibin was achieved by injection of inhibin antiserum. Effects on follicle population, timing of sexual maturation, ovulation rate at first and second oestrus and serum FSH levels were studied. Rats were injected with antiserum, (non-immune) control serum from castrated sheep (castrated serum) or their IgG fractions, or with saline on day 33 or 3 or 2 days (days −3/−2) before the expected day of first ovulation, day 38·5±0·2 (n = 70). Blood was collected from different subgroups at 8, 24 and 48 h, and at first and second oestrus after injection. At necropsy, ovaries were histologically prepared for differential counting of follicles (48 h and first oestrus) and counting of corpora lutea (CL; first and second oestrus) as an index of ovulation rate. Results from rats injected with either serum or its IgG fraction were not different, as was the case when rats were injected with either castrated serum or saline. Thus, results from groups treated with antiserum and antiserum IgG were combined and labelled 'antiserum', and the castrated serum, castrated serum IgG and saline-treated groups were combined and labelled 'control'. The activity of inhibin-neutralizing antibodies in the circulation of antiserum-treated rats was reduced by 43% between 8 h and second oestrus after injection, as determined by the binding of purified bioactive radioiodinated 31 kDa bovine inhibin. After antiserum injection on day 33, more healthy antral follicles (vol. > 100 × 105 μm3, diameter > 260 μm) were present in the ovaries at 48 h (70·6 vs 54·4; P < 0·05) and at first oestrus (73·1 vs 50·8; P < 0·05) if first oestrus was reached within 5 days, but numbers were not different if first oestrus was more than 5 days after injection (52·6 vs 50·8). The number of CL after injection of antiserum on day 33 was increased at first oestrus compared with control (13·4±0·5, n = 30, vs 10·0±0·2, n = 40; P<0·001), an effect that was even more clearly present in antiserum-injected rats ovulating within 5 days (14·4±0·7, n = 20; P < 0·001). Rats injected with antiserum at days −3/−2 showed a doubling of ovulation rate at first oestrus when compared with control animals (21·5±0·8, n = 12, vs 10·5±0·2, n = 15; P < 0·001). No differences in the number of CL was seen at second oestrus. Age and body weight on the day of first ovulation were not influenced by antiserum treatment. Serum FSH was significantly (P < 0·01) increased at 8 h after antiserum injection on either day 33 or on days −3/−2 to a level of 250 and 800% of control levels respectively. Thus, injection with inhibin–neutralizing antiserum into prepubertal female rats resulted, through an increase in serum FSH concentration 8 h after injection, in the growth of additional numbers of healthy antral follicles. Supranormal ovulation rate occurred if antiserum injections were given within the last 5 days before first ovulation, with a maximal ovulation rate after injection on days −3/−2. The data support the view that, in the immature female rat during the last 5 days before the day of first ovulation, inhibin is (through its regulation of serum FSH levels) progressively involved in the control of follicle growth and ovulation rate. Journal of Endocrinology (1991) 130, 289–296

scholarly journals Female Mice Haploinsufficient for an Inactivated Androgen Receptor (AR) Exhibit Age-Dependent Defects That Resemble the AR Null Phenotype of Dysfunctional Late Follicle Development, Ovulation, and Fertility

Endocrinology ◽  
2007 ◽  
Vol 148 (8) ◽  
pp. 3674-3684 ◽  
Author(s):  
K. A. Walters ◽  
C. M. Allan ◽  
M. Jimenez ◽  
P. R. Lim ◽  
R. A. Davey ◽  
...  
Keyword(s):  
Androgen Receptor ◽  
Ovarian Function ◽  
Gene Dosage ◽  
Early Embryo ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Cell Stage ◽  
Gene Dosage Effect ◽  
Female Mice ◽  
Age Dependent

The role of classical genomic androgen receptor (AR) mediated actions in female reproductive physiology remains unclear. Female mice homozygous for an in-frame deletion of exon 3 of the Ar (AR−/−) were subfertile, exhibiting delayed production of their first litter (AR+/+ = 22 d vs. AR−/− = 61 d, P &lt; 0.05) and producing 60% fewer pups/litter (AR+/+: 8.1 ± 0.4 vs. AR−/−: 3.2 ± 0.9, P &lt; 0.01). Heterozygous females (AR+/−) exhibited an age-dependent 55% reduction (P &lt; 0.01) in pups per litter, evident from 6 months of age (P &lt; 0.05), compared with AR+/+, indicating a significant gene dosage effect on female fertility. Ovulation was defective with a significant reduction in corpora lutea numbers (48–79%, P &lt; 0.01) in 10- to 12- and 26-wk-old AR+/− and AR−/− females and a 57% reduction in oocytes recovered from naturally mated AR−/− females (AR+/+: 9.8 ± 1.0 vs. AR−/−: 4.2 ± 1.2, P &lt; 0.01); however, early embryo development to the two-cell stage was unaltered. The delay in first litter, reduction in natural ovulation rate, and aromatase expression in AR+/− and AR−/− ovaries, coupled with the restored ovulation rate by gonadotropin hyperstimulation in AR−/− females, suggest aberrant gonadotropin regulation. A 2.7-fold increase (AR+/+: 35.4 ± 13.4 vs. AR−/−: 93.9 ± 6.1, P &lt; 0.01) in morphologically unhealthy antral follicles demonstrated deficiencies in late follicular development, although growing follicle populations and growth rates were unaltered. This novel model reveals that classical genomic AR action is critical for normal ovarian function, although not for follicle depletion and that haploinsufficiency for an inactivated AR may contribute to a premature reduction in female fecundity.

Prepubertal reduction of the ovarian follicle population by combined LH-releasing hormone antagonist treatment and unilateral ovariectomy influences follicle characteristics but not the ovulation rate at first oestrus

1992 ◽  
Vol 135 (3) ◽  
pp. 439-446 ◽  
Author(s):  
W. A. van Cappellen ◽  
E. C. M. van Leeuwen ◽  
P. Kramer ◽  
H. M. A. Meijs-Roelofs
Keyword(s):  
Ovarian Follicle ◽  
Ovarian Follicles ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Normal Range ◽  
Juvenile Period ◽  
Unilateral Ovariectomy ◽  
Releasing Hormone ◽  
Total Pool ◽  
Lh Releasing Hormone

ABSTRACT The effect on first ovulation of the massive reduction of the total pool of ovarian follicles during the infantile and late juvenile period was studied in rats. Treatment with an LH-releasing hormone antagonist (LHRH-A) during infancy (5 mg/kg body weight on days 6, 9, 12 and 15 of life) was combined with unilateral ovariectomy performed on either day 15 (early ULO) or 2–5 days before the expected day of first ovulation (late ULO). Rats were killed on the day of first or second oestrus, when blood was collected and the (remaining) ovaries were prepared for differential counting of follicles and corpora lutea. In addition, blood was sampled 8 h after ULO and the ovaries studied histologically in the group of rats which were unilaterally ovariectomized 2–5 days before first ovulation. The time of first ovulation was not influenced by treatment with LHRH-A, early or late ULO, or a combination of LHRH-A treatment and ULO. Ovulation rate after LHRH-A treatment was decreased, but was still within the normal range in intact rats and in early ULO rats compared with saline-treated controls. Serum FSH concentrations 8 h after ULO performed 2–5 days before first ovulation were similar in saline- and LHRH-A-treated rats (845 ± 59 and 801 ± 99 (s.e.m.) μg/l respectively) and had increased compared with intact controls (216 ± 15 μg/l). Treatment with LHRH-A resulted in a reduction of more than 50% in healthy and atretic follicles, and late ULO reduced the number of healthy follicles even further. In saline-treated rats late ULO decreased the rate of atresia, but in LHRH-A-treated rats atresia was not reduced further by (late or early) ULO. It is concluded that even after massive reduction of the pool of ovarian follicles by early LHRH-A treatment combined with late or early ULO, the timing of the first ovulation was normal and ovulation rates, although somewhat lower in some LHRH-A-treated rats, were within the normal range. Journal of Endocrinology (1992) 135, 439–446

scholarly journals Effects of a long-acting gonadotrophin-releasing hormone agonist (Leuprolide) on ovarian follicular development in prepubertal heifer calves

1994 ◽  
Vol 74 (4) ◽  
pp. 649-656 ◽  
Author(s):  
A. C. O. Evans ◽  
N. C. Rawlings
Keyword(s):  
Gnrh Agonist ◽  
Follicular Development ◽  
Ovarian Follicles ◽  
Follicular Growth ◽  
Long Term Effects ◽  
Releasing Hormone ◽  
Gonadotrophin Secretion ◽  
Gonadotrophin Releasing Hormone ◽  
Ovarian Follicular Development ◽  
Ovarian Follicular Growth

We studied the effects of reducing gonadotrophin secretion on ovarian follicular development in young prepubertal heifer calves. Calves received a GnRH agonist (n = 5, 15 mg of Leuprolide acetate, i.m.) or carrier (n = 5) at 8 and 12 w of age. Starting at 8 and 34 w of age, ovarian follicles were monitored daily for 17 d, and at 10, 15, 25 and 35 w of age, blood samples were collected every 15 min for 12 h for measurement of serum concentration of LH and FSH. GnRH agonist treatment did not affect the age and body weight at puberty (P > 0.05). Agonist treatment suppressed follicle numbers and in two heifers follicle emergence (growth above 4–5 mm) was blocked immediately. In three agonist-treated heifers, follicle emergence was blocked after one extended wave of follicular growth. At 34 w of age the pattern of ovarian follicular growth did not differ between groups but oestradiol secretion was lower in agonist-treated heifers. During agonist treatment basal and mean concentrations of FSH, and LH and FSH pulse amplitude were decreased but basal LH concentrations increased (P < 0.05). At 25 and 35 w of age some rebound in gonadotrophin secretion was seen.We concluded that disrupting gonadotrophin secretion in young prepubertal heifer calves by GnRH agonist treatment, suppressed ovarian follicular growth but that a rebound in gonadotrophin secretion prevented long term-effects on sexual development. Key words: Follicle stimulating hormone, gonadotrophin-releasing hormone, heifer calves, luteinising hormone ovarian follicles

Physiological mechanisms of ovarian follicular growth in pigs — A review

2008 ◽  
Vol 56 (3) ◽  
pp. 369-378 ◽  
Author(s):  
Tomasz Schwarz ◽  
Marcin Kopyra ◽  
Jacek Nowicki
Keyword(s):  
Selection Process ◽  
Follicular Development ◽  
Oestrous Cycle ◽  
Corpora Lutea ◽  
Significant Heterogeneity ◽  
Follicular Growth ◽  
Physiological Mechanisms ◽  
The Relationship ◽  
Ovarian Follicular Growth ◽  
Insight Into

Follicular growth after antrum formation is determined by follicle-stimulating hormone (FSH). Only two ways are possible for recruited follicles, continuing development or atresia. In gilts, intensive ovarian follicular growth begins between 60 and 100 days of age, and fluctuations of the ovarian morphological status last about 20 days; however, at that time there are no really large follicles. Final follicular development is under luteinising hormone (LH) control; this is why the attainment of puberty is related to an increase in serum oestradiol to a level that causes a preovulatory surge of this gonadotropin. The pool of follicles at the beginning of the oestrous cycle is about 30–40, most of which are small (< 3 mm) and growing. Then, the pool of follicles increases to about 80 in the mid-luteal phase but about 50 of them are small and 30 are medium sized (3–6.9 mm). Some of these follicles are in the growing phase, but some are atretic. Between days 7 and 15 of the oestrous cycle the percentage of atretic follicles fluctuates between 12 and 73%. At that time there are no large (> 7 mm) follicles because of the suppressing effect of progesterone. The number of small follicles declines after luteolysis. From the pool of medium follicles, large follicles are selected under the influence of LH, but about 70% of the medium-sized follicles become atretic. Because of the long-lasting selection process there is a significant heterogeneity in the diameter of large follicles in oestrus. However, the number of follicles correlates with the number of corpora lutea after ovulation. Individual follicular development and the relationship between follicles are still poorly known. The use of ultrasonography may give a closer insight into these phenomena.

scholarly journals MORPHOLOGY AND RESPONSIVENESS OF THE TWO LARGEST OVARIAN FOLLICLES IN ANESTROUS EWES

1977 ◽  
Vol 57 (3) ◽  
pp. 459-464 ◽  
Author(s):  
PIERRE MATTON ◽  
JACQUES BHÉREUR ◽  
J. J. DUFOUR
Keyword(s):  
Breeding Season ◽  
Ovarian Follicles ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
India Ink

The morphology and the responsiveness of ovarian follicles to an ovulating stimulus imposed in the presence or absence of previously induced corpora lutea (CL) were studied in anestrous DLS ewes (Dorset × Leicester × Suffolk). Induction of CL formation was done with 500 IU of PMSG given intravenously. In CL-bearing ewes, the diameter of the largest follicle was significantly larger 12 and 16 days after PMSG injection, while that of the second largest follicle was increased only on day 12. When ovulation was induced with 500 IU PMSG on day 16, the presence of a previously induced CL did not modify the ovulation rate. The two largest follicles identified with India ink markings 4 days prior to PMSG injection did not respond by ovulation and most of these follicles had become completely atretic by day 21 of the experiment. When the two largest follicles, however, were identified and marked on the day of PMSG injection, 65% of them responded to the stimulus. This indicated that turnover of the large follicles was occurring during the anestrous season as is the case during the normal breeding season.

scholarly journals Subchronic and Low Dose of Tributyltin Exposure Leads to Reduced Ovarian Reserve, Reduced Uterine Gland Number, and Other Reproductive Irregularities in Female Mice

2020 ◽  
Vol 176 (1) ◽  
pp. 74-85 ◽  
Author(s):  
Isabela V Sarmento ◽  
Eduardo Merlo ◽  
Silvana S Meyrelles ◽  
Elisardo C Vasquez ◽  
Genoa R Warner ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ovarian Reserve ◽  
Low Dose ◽  
Reproductive Tract ◽  
Ovarian Follicles ◽  
Corpora Lutea ◽  
Female Mice ◽  
Uterine Gland ◽  
Follicular Reserve ◽  
And Oxidative Stress

Abstract Tributyltin (TBT) chloride is an endocrine disrupting chemical associated with reproductive complications. Studies have shown that TBT targets the reproductive tract, impairing ovarian folliculogenesis, and uterine morphophysiology. In this investigation, we assessed whether subchronic and low dose of TBT exposure results in abnormal ovarian follicular reserve and other irregularities in female mice. TBT was administered to female mice (500 ng/kg/day for 12 days via gavage), and reproductive tract morphophysiology was assessed. We further assessed reproductive tract inflammation and oxidative stress. Improper functioning of the reproductive tract in TBT mice was observed. Specifically, irregular estrous cyclicity and abnormal ovarian morphology coupled with reduction in primordial and primary follicle numbers was observed, suggesting ovarian reserve depletion. In addition, improper follicular development and a reduction in antral follicles, corpora lutea, and total healthy ovarian follicles together with an increase in cystic follicles were apparent. Evidence of uterine atrophy, reduction in endometrial gland number, and inflammation and oxidative stress were seen in TBT mice. Further, strong negative correlations were observed between testosterone levels and primordial, primary, and total healthy ovarian follicles. Thus, these data suggest that the subchronic and low dose of TBT exposure impaired ovarian follicular reserve, uterine gland number, and other reproductive features in female mice.

EFFECTS OF •1–24 SYNTHETIC CORTICOTROPHIN ON REPRODUCTIVE TRACT AND KIDNEYS OF IMMATURE FEMALE MICE

1967 ◽  
Vol 55 (1) ◽  
pp. 62-70 ◽  
Author(s):  
John J. Christian
Keyword(s):  
Reproductive Tract ◽  
Reproductive Function ◽  
Corpora Lutea ◽  
Immature Female ◽  
Intact Mouse ◽  
Renal Lesions ◽  
Female Mice ◽  
Glomerular Lesions ◽  
Distal Tubules ◽  
Glomerular Capillaries

ABSTRACT Four units of synthetic β1–24 corticotrophin (Ciba) were given daily to 12 sham-adrenalectomized (»intact«) and to 12 adrenalectomized female mice beginning at 33–39 days of age. Adrenalectomy was at 24–30 days of age and daily injections of 50 μg of cortisol acetate were begun at once. Synthetic corticotrophin (ACTH), like porcine ACTH, inhibited reproductive function in intact and adrenalectomized mice. One intact mouse had degenerate corpora lutea, but the other intact mice had none. There were no ripe follicles and uteri were anoestrous and usually mucified. Effects of synthetic ACTH in adrenalectomized mice were similar but less marked. This ACTH resulted in glomerular lesions similar to those produced by highly purified porcine ACTH at a roughly comparable dose (4 IU). Lesions were marked by an increase in intercapillary weakly PAS+, fibrillar-appearing material, increased size and cellularity of tuft, reduction in number and peripheralization of patent glomerular capillaries, and occasional deposits of brightly PAS positive material in the tufts, juxtaglomerular regions, and at bases of epithelial cells of distal tubules in proximity to glomeruli. Since β1–24 ACTH is very weakly antigenic compared to β1–24 or natural ACTH, it is unlikely that the production of renal lesions and inhibition of reproductive function result from an immune response and therefore is probably an inherent extra-adrenal action of the β1–24 ACTH core. Other pertinent effects of the synthetic ACTH are given.

scholarly journals Effect of inbreeding on ovulation rate and foetal mortality in mice

1960 ◽  
Vol 1 (3) ◽  
pp. 422-430 ◽  
Author(s):  
D. S. Falconer ◽  
R. C. Roberts
Keyword(s):  
Developmental Stage ◽  
Litter Size ◽  
Pregnant Female ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Female Mice ◽  
Inbreeding Coefficients ◽  
Foetal Mortality ◽  
Implantation Sites ◽  
Post Implantation

Dissections were made of 16-day-pregnant female mice with the object of discovering the developmental stage at which litter size is reduced by inbreeding. Counts were made of the numbers of corpora lutea, implantation sites, and live embryos, and comparisons were made between females with inbreeding coefficients of 50–60% and non-inbred females. Except in one group the embryos were all non-inbred, so that the comparisons showed the effect of inbreeding in the mother of the litter. No influence of inbreeding in the male parent was found.The only difference found between inbred and non-inbred females was in the number of eggs or embryos lost before implantation. The greater pre-implantation loss in inbred females was enough to account for the smaller number of young born alive in their litters.There was no difference between the inbred and non-inbred females in the ovulation rate, measured by the number of corpora lutea, or in the post-implantation mortality of the embryos.There was a positive correlation between ovulation rate and weight at 6 weeks. For reasons explained in the Discussion, the inbred females did not differ in weight from the non-inbred females. If, under other conditions, the weight declined on inbreeding, the ovulation rate would be expected to decline also.

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