OVARIAN FOLLICULAR DEVELOPMENT LEADING TO FIRST OVULATION AND ACCOMPANYING GONADOTROPHIN LEVELS AS STUDIED IN THE UNILATERALLY OVARIECTOMIZED RAT

1982 ◽  
Vol 92 (3) ◽  
pp. 341-349 ◽  
Author(s):  
H. M. A. MEIJS-ROELOFS ◽  
P. OSMAN ◽  
P. KRAMER

Ovarian follicular development was studied in the rat during a 15-day period preceding first ovulation. Ovaries were obtained by unilateral ovariectomy performed at various ages and the rats were allowed to live until the day after first ovulation. The timing of this ovulation was compared with that in unoperated, paired control rats of the same age. For estimation of gonadotrophin levels, blood was taken from the paired control rats at the time when experimental rats were unilaterally ovariectomized. There was no evidence that unilateral ovariectomy had any influence on the timing of first ovulation. Therefore the ovaries obtained could be dated in relation to first ovulation, and follicular growth during the final prepubertal period could thus be studied in a genuine developmental sequence. Results revealed that follicular growth leading to first ovulation starts at ±8 days before this ovulation; follicular processes taking place are comparable to those found during the adult 5-day cycle but proceed more slowly. Gonadotrophin concentrations accompanying the follicular dynamics and measured at 11·00 h, showed a clear tendency for FSH concentrations to decrease with increasing age, i.e. approaching first ovulation. Concentrations of LH did not show a definite pattern and were generally low, although in some individual rats relatively high LH values (> 100 μg/l) were found in the period of 5–3 days before first ovulation.

2016 ◽  
Vol 5 (1) ◽  
pp. 43-48
Author(s):  
Manoj Bhattarai

Background Ultrasonography is the first line imaging modality for evaluation of ovaries, monitoring ovarian follicular development and detecting ovulation in infertile women; thus plays a significant role in infertility management. This study was undertaken to evaluate the pattern of ovarian follicular growth and to predict and detect ovulation in infertile women by transvaginal sonography in eastern region of Nepal.Material and Methods Hospital based prospective cross-sectional study on 100 infertile patients referred for ultrasonographic monitoring of ovarian follicle was conducted over duration of 26 months. Serial transvaginal sonography of the patients was performed using standard procedure daily from day 10 of menstrual cycle till detection of ovulation. Identification of ovarian dominant follicle, monitoring of dominant follicle development and detection of ovulation was assessed in relation to the day of menstrual cycle.Results Increase in mean diameter of the dominant follicle was seen in serial ultrasound scan till ovulation, which occurred in all cases by day 16 of menstrual cycle. The average daily follicular growth rate ± SD from day 10 of menstrual cycle till detection of ovulation was 2.2 ± 0.2 mm per day and the mean diameter ± SD of dominant follicle on the day prior to ovulation was 21.4 ± 2.8 mm (range: 17.2 – 26.3 mm).Conclusion Transvaginal sonography is an excellent method for monitoring of ovarian follicular development and shows a linear increase in mean diameter of dominant follicle from day 10 of menstrual cycle till detection of ovulation.Journal of Nobel Medical CollegeVolume 5, Number 1, Issue 8, January-July 2016, 43-48


1994 ◽  
Vol 74 (4) ◽  
pp. 649-656 ◽  
Author(s):  
A. C. O. Evans ◽  
N. C. Rawlings

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


1986 ◽  
Vol 112 (2) ◽  
pp. 247-252 ◽  
Author(s):  
P. van der Schoot ◽  
W.J. de Greef

Abstract. Ovarian follicular development was studied during lactation in rats. At an early stage of lactation (day 7) the ovaries showed only small follicles in agreement with the expected 'follicular quiescence' during lactation. However, at a more advanced stage of lactation (day 14), there were large follicles which were capable of ovulation in response to exogenous gonadotropins. Unilateral ovariectomy early during lactation (day 2) resulted in compensatory follicular development in the remaining ovary. However, doubling of the number of large follicles per ovary had not yet occurred by day 13. Unilateral ovariectomy caused a significant prolongation of the delay of embryonic implantation in pregnant lactating rats: this probably reflected delay of the development of sufficiently large numbers of oestrogen-producing follicles for this process. Unilateral ovariectomy did not affect the length of lactational pseudopregnancy. The findings indicate that 'follicular quiescence' during lactation in rats is limited to the very first period after parturition. This limitation may result from the relative ineffectiveness of suckling to suppress the secretion of FSH. In this respect, ovarian follicular development in rats differs from that in many other species, including primates and man.


1975 ◽  
Vol 66 (2) ◽  
pp. 249-256 ◽  
Author(s):  
W. J. DE GREEF ◽  
J. DULLAART ◽  
G. H. ZEILMAKER

SUMMARY Serum LH, FSH, prolactin and progesterone concentrations and follicular size were measured in rats during pseudopregnancy after unilateral ovariectomy (ULO) on day 1. This operation did not affect the duration of pseudopregnancy. Following pseudopregnancy compensatory ovulation occurred. After ULO progesterone concentrations remained low as compared with control values but the progesterone secretion per ovary was increased slightly. After ULO, LH concentrations were significantly increased on days 3 and 4 of pseudopregnancy. FSH concentrations were increased 5 h after the operation and again on days 4–7 of pseudopregnancy when compared with sham-operated control animals. During pseudopregnancy prolactin secretion increased each night. Increased prolactin levels were observed 18 and 36 h after ULO. The number of medium-sized follicles had increased 24 h after ULO. From the present study it is concluded that progesterone secretion by the corpora lutea can be increased to a limited degree by the increased release of gonadotrophins. Furthermore, it is concluded that a rapid increase in FSH concentrations after ULO is responsible for the initiation of the compensatory follicular growth.


2010 ◽  
Vol 55 (No. 6) ◽  
pp. 234-242 ◽  
Author(s):  
J. Šichtaø ◽  
R. Tolman ◽  
R. Rajmon ◽  
P. Klabanová ◽  
P. Berka ◽  
...  

Differences in follicular development and repeatability of follicular growth pattern among Czech Fleckvieh (n = 20) and Holstein (n = 23) heifers were investigated. Follicular dynamics was evaluated by daily sonographic scanning during three interovulatory intervals. The mean duration of the interovulatory interval was 20.66 &plusmn; 0.32 days, no differences between breeds were observed. The proportion of the non-alterna-ting pattern was nearly the same as that of the alternating pattern (54% and 46%, respectively). The majority of IOIs &le; 21 days were of the 2-wave pattern (71%) whereas only 29% of them were of the 3-wave pattern. Conversely, the majority of IOIs &ge; 22 days were of the 3-wave pattern (84%), whereas only 16% were of the 2-wave pattern. Differences could be observed in the Czech Fleckvieh heifers. Comparing 2- and 3-wave interovulatory intervals, 44.2% of the heifers exhibited 3 waves and 55.8% of the heifers exhibited 2 waves of follicular growth. The ratio of 3- to 2-wave heifers was about the same in the Holstein breed; in Czech Fleckvieh 2-wave cycles slightly dominated (11/12, 8/12; respectively). In Holstein heifers, the first follicular wave occurred 0.92 &plusmn; 0.15 days after ovulation in 2-wave interovulatory intervals, and the emergence of the first wave in 2-wave Czech Fleckvieh heifers appeared later (P &lt; 0.05), 1.83 &plusmn; 0.3 days after ovulation. The maximal size reached by the dominant follicles in all animals and in the Czech Fleckvieh differed in the first and in the second wave of 2-wave cycles (P &lt; 0.05). In 3-wave interovulatory intervals the dominant follicles in the second wave differed (P &lt; 0.05) from the mean diameters of the first and the third wave in the Czech Fleckvieh. The ovulatory follicles were significantly (P &lt; 0.05) smaller in 2-wave than in 3-wave interovulatory intervals among all animals and between the Holstein and Czech Fleckvieh heifers. In conclusion, we found a similar pattern of ovarian follicular dynamics in Czech Fleckvieh and Holstein heifers kept under identical nutritional and environmental conditions. Whether the significant difference in the emergence of the 1st fol-licular wave in 2-wave IOIs between C and H heifers is of real biological significance is ambiguous.


1972 ◽  
Vol 69 (2) ◽  
pp. 267-280 ◽  
Author(s):  
Richard D. Peppler

ABSTRACT Intact 5-day cycling rats were killed between 8–10 a. m. on each day of the oestrous cycle; experimental rats were unilaterally ovariectomized (ULO) at 9 a. m. on day 1 (oestrus) and killed between 8 and 10 a. m. on days 2, 3, 4 or 1 of the subsequent cycle. Pituitary and plasma concentrations of FSH and LH were measured in both groups of rats. Pituitary FSH concentration was measured by the Steelman-Pohley method with slight modification; plasma FSH by the Igarashi-McCann assay and pituitary and plasma LH concentration by the OAAD method. In intact rats, pituitary FSH values remained constant for the first three days of the cycle, increased on day 4 and reverted to early cycle values by day 5. Plasma FSH increased between days 2 and 3 and days 5 and 1. Pituitary LH concentration remained the same for days 1 and 2; increased two-fold on days 3 and 4, and increased further by day 5. Plasma LH increased between days 2 and 3; other differences between successive cycle days were not apparent. Following ULO on day 1, pituitary FSH increased steadily, but not significantly, for the remaining cycle. Plasma FSH did not change from day 2 through day 1 of the subsequent cycle. Pituitary LH remained low on day 2, increased sharply by day 3 and decreased (50 %) by day 4. Plasma LH also increased between days 2 and 3. Other differences between successive days following unilateral ovariectomy on day 1 were not apparent. Correlation of gonadotrophin activity with follicular development suggests that the mechanism of compensatory ovulation in the rat may be one of an increase in time of exposure to a constant gonadotrophic level for the duration of the oestrous cycle rather than to increased levels of the gonadotrophin.


Author(s):  
Annia A. Martínez-Peña ◽  
Kendrick Lee ◽  
James J. Petrik ◽  
Daniel B. Hardy ◽  
Alison C. Holloway

Abstract With the legalization of marijuana (Cannabis sativa) and increasing use during pregnancy, it is important to understand its impact on exposed offspring. Specifically, the effects of Δ-9-tetrahydrocannabinol (Δ9-THC), the major psychoactive component of cannabis, on fetal ovarian development and long-term reproductive health are not fully understood. The aim of this study was to assess the effect of prenatal exposure to Δ9-THC on ovarian health in adult rat offspring. At 6 months of age, Δ9-THC-exposed offspring had accelerated folliculogenesis with apparent follicular development arrest, but no persistent effects on circulating steroid levels. Ovaries from Δ9-THC-exposed offspring had reduced blood vessel density in association with decreased expression of the pro-angiogenic factor VEGF and its receptor VEGFR-2, as well as an increase in the anti-angiogenic factor thrombospondin 1 (TSP-1). Collectively, these data suggest that exposure to Δ9-THC during pregnancy alters follicular dynamics during postnatal life, which may have long-lasting detrimental effects on female reproductive health.


1995 ◽  
Vol 39 (3) ◽  
pp. 183-192 ◽  
Author(s):  
H. Twagiramungu ◽  
L.A. Guilbault ◽  
J.G. Proulx ◽  
R. Ramkumar ◽  
J.J. Dufour

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