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

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.

Reproduction ◽  
2014 ◽  
Vol 147 (2) ◽  
pp. 189-197 ◽  
Author(s):  
Noriyuki Takahashi ◽  
Wataru Tarumi ◽  
Bunpei Ishizuka

Most of the previous studies on ovarian hyaluronan (HA) have focused on mature antral follicles or corpora lutea, but scarcely on small preantral follicles. Moreover, the origin of follicular HA is unknown. To clarify the localization of HA and its synthases in small growing follicles, involvement of HA in follicle growth, and gonadotropin regulation of HA synthase (Has) gene expression, in this study, perinatal, immature, and adult ovaries of Wistar-Imamichi rats were examined histologically and biochemically and byin vitrofollicle culture. HA was detected in the extracellular matrix of granulosa and theca cell layers of primary follicles and more advanced follicles. Ovarian HA accumulation ontogenetically started in the sex cords of perinatal rats, and its primary site shifted to the intrafollicular region of primary follicles within 5 days of birth. TheHas1–3mRNAs were expressed in the ovaries of perinatal, prepubertal, and adult rats, and the expression levels ofHas1andHas2genes were modulated during the estrous cycle in adult rats and following administration of exogenous gonadotropins in immature acyclic rats. TheHas1andHas2mRNAs were predominantly localized in the theca and granulosa cell layers of growing follicles respectively. Treatments with chemicals known to reduce ovarian HA synthesis induced follicular atresia. More directly, the addition ofStreptomyceshyaluronidase, which specifically degrades HA, induced the arrest of follicle growth in anin vitroculture system. These results indicate that gonadotropin-regulated HA synthesis is involved in normal follicle growth.


2008 ◽  
Vol 20 (9) ◽  
pp. 71
Author(s):  
M. Bertoldo ◽  
P. K. Holyoake ◽  
G. Evans ◽  
C. G. Grupen

Reduced farrowing rate caused by embryonic mortality is a manifestation of seasonal infertility in pigs. The ability of the oocyte to mature, be fertilised and sustain embryonic development is acquired gradually by the oocyte throughout folliculogenesis. This study was undertaken to determine if seasonal differences in ovarian morphology are associated with reduced reproductive performance displayed during seasonal infertility. Sows culled after weaning were sourced from two genetically distinct herds (Farms A and B). Pairs of ovaries were collected from sows 4 days post-weaning during winter (n = 131) and summer (n = 275). Ovarian weight (Farm A only) and the numbers of small (3–4 mm) and large (5–8 mm) follicles were assessed (Farms A and B). Data did not follow normality and was analysed using the Mann–Whitney test. Mean ovarian weight per sow during winter (20.0 ± 1.3 g) was significantly heavier than that during summer (15.3 ± 0.8 g; P < 0.05). Farm A ovaries had a greater total number of antral follicles in winter compared with summer, and a greater number of antral follicles in winter compared with Farm B ovaries (P < 0.05). In Farm A ovaries, the proportion of follicles that were large was greater in summer compared with winter (78% v. 66%; P < 0.05), but the follicular distribution did not change with season in Farm B ovaries. While the findings demonstrate that ovarian weight was greater in winter compared with summer, they suggest that this difference was not the result of changes in the number or distribution of surface antral follicles. The difference in ovarian weight is possibly due to differences in ovarian tissue resulting from regressed corpora lutea. Further studies are being undertaken to assess the effect of season on oocyte developmental competence and the steroid content of follicular fluid isolated from small and large follicles.


Reproduction ◽  
2008 ◽  
Vol 136 (1) ◽  
pp. 9-21 ◽  
Author(s):  
Ikkou Kawashima ◽  
Tetsuji Okazaki ◽  
Noritaka Noma ◽  
Masahide Nishibori ◽  
Yasuhisa Yamashita ◽  
...  

In this study, we collected follicular fluid, granulosa cells, and cumulus cells from antral follicles at specific time intervals following equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) treatment of gilts. The treatment with eCG increased the production of estrogen coordinately with up-regulated proliferation of granulosa and cumulus cells. eCG also induced the expression ofLHCGRandPGRin cumulus cells and progesterone accumulation was detected in follicular fluid prior to the LH/hCG surge. Moreover, progesterone and progesterone receptor (PGR) were critical for FSH-inducedLHCGRexpression in cumulus cells in culture. The expression ofLHCGRmRNA in cumulus cells was associated with the ability of LH to induce prostaglandin production, release of epidermal growth factor (EGF)-like factors, and a disintegrin and metalloprotease with thrombospondin-like repeats 1 expression, promoting cumulus cell oocyte complexes (COCs) expansion and oocyte maturation. Based on the unique expression and regulation ofPGRandLHCGRin cumulus cells, we designed a novel porcine COCs culture system in which hormones were added sequentially to mimic changes observedin vivo. Specifically, COCs from small antral follicles were pre-cultured with FSH and estradiol for 10 h at which time progesterone was added for another 10 h. After 20 h, COCs were moved to fresh medium containing LH, EGF, and progesterone. The oocytes matured in this revised COC culture system exhibited greater developmental competence to blastocyst stage. From these results, we conclude that to achieve optimal COC expansion and oocyte maturation in culture the unique gene expression patterns in cumulus cells of each species need to be characterized and used to increase the effectiveness of hormone stimulation.


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

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


1954 ◽  
Vol 11 (4) ◽  
pp. 359-376 ◽  
Author(s):  
ANITA M. MANDL

SUMMARY The sensitivity of adrenalectomized, control-operated and unoperated rats to pregnant mare serum (PMS) and chorionic gonadotrophin (CG) has been studied. A total of 638 mature and immature female rats was used. The ovaries of adrenalectomized rats were found to contain fewer large follicles and corpora lutea than those of control-operated litter-mates, and the slight ovarian hypertrophy which occurs after surgical trauma was found to be due to an increase in the number of Graafian follicles and corpora lutea. Further experiment showed that, as judged by the weight of the ovaries, adrenalectomy reduces the ovarian reaction to injected PMS (10 i.u./day) in both adult and immature rats. Replacement therapy with DCA (1 mg/day) failed to re-establish the normal response in adults. Treatment with cortisone (1 mg/day) restored the normal reaction in both adult and immature adrenalectomized rats. Adrenalectomized adult rats responded to injected CG (10 i.u./day) as vigorously as their operated and unoperated litter-mates. On the other hand, immature adrenalectomized animals did not respond fully to CG. Treatment with cortisone again fully restored the normal reaction.


2006 ◽  
Vol 18 (4) ◽  
pp. 477 ◽  
Author(s):  
C. H. McDonald ◽  
D. A. Taggart ◽  
W. G. Breed ◽  
G. V. Druery ◽  
G. A. Shimmin ◽  
...  

The effect of the exogenous administration of porcine follicle-stimulating hormone (pFSH) and pregnant mare serum gonadotrophin (PMSG) on ovarian follicular development and oocyte maturation in the southern hairy nosed wombat Lasiorhinus latifrons was investigated. Three experimental groups were administered pFSH at various doses and for different treatment lengths, followed by 25 mg porcine luteinising hormone (pLH) 12 h after the last dose of pFSH. Another group was given PMSG followed 72 h later by 25 mg pLH. Animals were killed 24 h after pLH. The left ovary was fixed for histology and the morphology of the antral follicles was determined, whereas follicular oocytes in the right ovary were aspirated, fixed, stained with 4′,6′-diamidino-2-phenylindole, and viewed for nuclear maturation. There was no significant difference in the mean number of ovarian follicles >1 mm, or in the size class of follicles assessed between control and experimental groups. However, a trend was observed suggesting a possible increase in follicles >3.0 mm in experimental groups compared with control animals. In all females administered exogenous porcine gonadotrophins, but not controls, some of the mural granulosa cells of large tertiary antral follicles had markedly enlarged nuclei (approximately 14 µm in diameter). All oocytes from the control group remained at the germinal vesicle stage, whereas approximately 40% of oocytes retrieved from the pFSH groups and 82.4% retrieved from the PMSG-primed animals had undergone germinal vesicle break down, with a small number reaching meiosis II. The present study shows that exogenous administration of either pFSH or PMSG to hairy nosed wombats can induce follicular growth and oocyte maturation. Such findings could be useful in the development of reproductive technology in this species.


2002 ◽  
Vol 173 (2) ◽  
pp. 297-304 ◽  
Author(s):  
MJ Engelbregt ◽  
MM van Weissenbruch ◽  
C Popp-Snijders ◽  
HA Delemarre-van de Waal

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.


Author(s):  
A.A. Mohammed ◽  
T. Al-Shaheen ◽  
S. Al-Suwaiegh

Oocytes are bathed in extracellular fluid of the antral follicles, which is termed follicular fluid (FF). Follicular fluid is synthesized from secretions of theca, granulosa, and cumulus cells and from a transudate of blood plasma. Oocytes persist in meiotic arrest in antral follicles until luteinizing hormone (LH) surge or removal the oocytes from the ovarian follicles. This suggests that FF before LH surge might contain meiosis inhibiting factor(s). The microvasculatory bed of the follicular wall and the composition of FF undergo changes during follicular growth and development, which is important for oocyte maturation and subsequent embryo development. Therefore, it is expected that FF composition and components might change according to timing of FF aspiration from follicles. Hence, negative or positive effects could be expected when FF supplemented during oocyte maturation in vitro. Nutrition effects on microvasculatory bed of follicles and their sizes. Thus, the nutritional status of animals is a factor affected on oocyte maturation and embryo development. The present article reviews and discusses these effects.


1976 ◽  
Vol 68 (3) ◽  
pp. 461-468 ◽  
Author(s):  
J. TH. J. UILENBROEK ◽  
E. ARENDSEN DE WOLFF-EXALTO ◽  
M. A. BLANKENSTEIN

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.


1981 ◽  
Vol 241 (3) ◽  
pp. E221-E225 ◽  
Author(s):  
K. Taya ◽  
G. S. Greenwald

Thirty-day-old rats given a single subcutaneous injection of 5 IU pregnant mare serum gonadotropin (PMS) at 0900 h ovulated on the morning of day 33 (= estrus). However, the second ovulation did not occur until 9.4 days later. To determine the mechanism responsible for the delay in the second ovulation, in vivo and in vitro determinations of steroid and peptide hormones were compared between PMS-primed immature rats and adult cyclic rats. In PMS-primed rats, the corpora lutea (CL) produced progesterone for 2 days longer (until day 36) than the CL of the adult rat. Serum levels of 20 alpha-dihydroprogesterone, testosterone, and estradiol in PMS-primed rats were significantly lower than the corresponding values in adult rats. Serum LH was consistently lower in the PMS-primed rats. An increase in serum FSH occurred on days 36–37, which may be responsible for maturation of the follicles destined to ovulate at the second ovulation. On day 37, the nonluteal ovary of the PMS-primed rats also began to produce in vitro appreciable amounts of testosterone and estradiol. These findings suggest that the greater levels of prolactin and/or low levels of luteinizing hormone during estrus in PMS-primed rats may be responsible for the prolonged secretion of progesterone by the CL. This in turn inhibits follicular maturation, indirectly by lowering serum LH, which is reflected in reduced ability of the follicles in vitro to produce testosterone and estradiol until the CL regress.


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