SERUM LUTEINIZING HORMONE, FOLLICLE-STIMULATING HORMONE, PROLACTIN AND PROGESTERONE CONCENTRATIONS AND FOLLICULAR DEVELOPMENT IN THE PSEUDOPREGNANT RAT AFTER UNILATERAL OVARIECTOMY

1975 ◽  
Vol 66 (2) ◽  
pp. 249-256 ◽  
Author(s):  
W. J. DE GREEF ◽  
J. DULLAART ◽  
G. H. ZEILMAKER
Keyword(s):  
Follicular Development ◽  
Prolactin Secretion ◽  
Corpora Lutea ◽  
Follicular Growth ◽  
Unilateral Ovariectomy ◽  
Progesterone Secretion ◽  
Serum Luteinizing Hormone ◽  
Serum Lh ◽  
Follicular Size ◽  
Limited Degree

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.

Pineal denervation by cervical sympathetic ganglionectomy suppresses the role of photoperiod on pregnancy or pseudopregnancy, body weight and moulting periods in the mink (Mustela vison)

1985 ◽  
Vol 107 (1) ◽  
pp. 31-39 ◽  
Author(s):  
L. Martinet ◽  
D. Allain ◽  
Y. Chabi
Keyword(s):  
Body Weight ◽  
Environmental Factors ◽  
Prolactin Secretion ◽  
Corpora Lutea ◽  
Progesterone Secretion ◽  
Cervical Ganglion ◽  
Cervical Sympathetic ◽  
Implantation Period ◽  
Short Days

ABSTRACT In mink, termination of the delayed implantation period, following reactivation of the corpora lutea, and onset of the spring moult are associated with a rise in prolactin secretion triggered by increasing daylength, while decreasing daylength induces the autumn moult. To establish whether suppression of the function of the pineal rendered the mink unresponsive to daylength changes, the superior cervical ganglion was removed bilaterally 2–4 weeks before mating. Intact and operated females were then left outdoors or were put under a lighting regime of either 15 h light: 9 h darkness (15L: 9D) or 8L: 16D. In July, at the end of the spring moult, the 15L: 9D lighting regime was changed to one of 8L: 16D. Under artificial photoperiods ganglionectomy suppressed the stimulatory role of long days and the inhibitory role of short days on prolactin secretion, and consequently on progesterone secretion and spring moult. Neither was the autumn moult, induced early in intact females by the change to a short photoperiod, advanced in ganglionectomized females, showing that the latter were unresponsive to the artificial modification of the photoperiod. However, in animals kept outdoors, prolactin and progesterone secretion and spring moult were not changed by ganglionectomy. Increase in body weight and autumn moult were only slightly delayed by the operation suggesting that other environmental factors had replaced the synchronizing effect of the daylength changes. Alternatively the desynchronization between intact females responsive to photoperiodism and those rendered unresponsive may be too slow to be observed soon after ganglionectomy. J. Endocr. (1985) 107, 31–39

1 PROGESTERONE AS THE DRIVING REGULATORY FORCE BEHIND SERUM FSH CONCENTRATIONS AND ANTRAL FOLLICULAR GROWTH IN CYCLIC EWES

2010 ◽  
Vol 22 (1) ◽  
pp. 159
Author(s):  
T. E. Baby ◽  
P. M. Bartlewski
Keyword(s):  
Treatment Group ◽  
Estrous Cycle ◽  
Luteal Phase ◽  
Follicular Development ◽  
Serum Levels ◽  
Time Frame ◽  
Corpora Lutea ◽  
Research Station ◽  
Follicular Growth ◽  
Follicular Waves

Ovarian antral follicles in sheep grow in an orderly succession, producing typically 3 to 4 follicular waves per 17-day estrous cycle. Each wave is preceded by a transient increase in circulating FSH concentrations. The mechanism controlling the number of recurrent FSH peaks and emerging follicular waves remains unknown. During the ewe's estrous cycle, the time between the first 2 FSH peaks and days of wave emergence is longer than the intervals separating the ensuing FSH peaks and follicular waves. The prolonged inter-peak/inter-wave interval occurs early in the luteal phase when low levels of progesterone are secreted by developing, or non-fully functional, corpora lutea. The purpose of the present study was to determine the effect of varying progesterone (P4) levels on circulating concentrations of FSH and antral follicular development in sheep. Exogenous P4 (15 mg per ewe i.m.) was administered twice daily to 6 cycling Rideau Arcott × Dorset ewes from Day 0 (ovulation) to Day 4 (the mean duration of the inter-wave interval); 6 animals served as controls. Follicular growth was monitored in all animals by daily transrectal ultrasonography (Days 0 to 9). Jugular blood samples were drawn twice a day from Day 0 to 4 and then daily until Day 9 to measure systemic concentrations of P4 and FSH. The first FSH peak post-ovulation was detected on Day 1.4 ± 0.2 and 4.0 ± 0.2 in treated and control ewes, respectively (P < 0.05). The next FSH peak(s) occurred on Days 3.4 ± 0.3 and 5.2 ± 0.2 in the treatment group and on Day 5.5 ± 0.3 in controls. Consequently, the treatment group had, on average, 3 follicular waves emerging on Days 0, 3, and 6, whereas the controls produced 2 waves emerging on Days 0 and 5 (P < 0.05).We then retrospectively analyzed and compared daily serum concentrations of P4 and FSH obtained in cyclic Western White Face ewes (Columbia × Rambouillet) that had 3 (n = 10) or 4 (n = 19) follicular waves per cycle. Mean P4 concentrations were greater (P < 0.05) in sheep with 4 waves per cycle compared with their counterparts, which had 3 waves of follicular growth. Interestingly, the ewes with 3 waves exceeded (P < 0.05) all animals with 4 follicular waves in mean serum FSH concentrations on Days 0 to 2, 6 to 7, and 9 to 15 post-ovulation. In summary, creation of mid-luteal phase levels of P4 in metestrus shortened the time to the first post-ovulatory FSH peak in ewes, resulting in emergence of one more follicular wave compared with control animals during the same time frame. The ewes exhibiting 4 waves of follicular emergence had greater serum levels of P4 but lower FSH concentrations compared with sheep with 3 waves per cycle. Therefore, progesterone appears to be a key endocrine signal governing the control of periodic increases in serum FSH concentrations and the number of follicular waves in cyclic sheep. This study was funded by OMAFRA and NSERC grants. Appreciation is extended to Norman C. Rawlings, Susan Cook, and Sekallu Srinivas (University of Saskatchewan) and the staff at Ponsonby Sheep Research Station.

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
Keyword(s):  
Follicular Development ◽  
Ovariectomized Rat ◽  
Follicular Growth ◽  
Developmental Sequence ◽  
Unilateral Ovariectomy ◽  
Clear Tendency ◽  
Paired Control ◽  
Definite Pattern ◽  
Ovarian Follicular Development ◽  
Follicular Dynamics

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.

Effect of supplemental lighting on puberty, follicular development, pituitary and serum concentrations of LH and hypothalamic content of GnRH in gilts

1990 ◽  
Vol 51 (2) ◽  
pp. 365-373 ◽  
Author(s):  
K. E. Brandt ◽  
M. A. Diekman ◽  
D. M. Grieger ◽  
G. E. Moss
Keyword(s):  
Preoptic Area ◽  
Follicular Development ◽  
Serum Concentrations ◽  
Detectable Change ◽  
Treatment Groups ◽  
Natural Lighting ◽  
Gland Weight ◽  
Serum Lh ◽  
Follicular Size ◽  
Supplemental Lighting

ABSTRACTOne hundred and thirty crossbred gilts (Yorkshire × Duroc × Hampshire) were exposed to either natural (40 lux) or supplemental lighting (700 lux) beginning at 8 weeks of age. Gilts received supplemental lighting from 40-W flourescent bulbs from 05·15 to 09·00 h and 16·30 to 20·15 h from 9 September to 22 April. At 4 months of age, all gilts were exposed daily for 15 min to mature boars five times weekly. Twelve gilts from each group were slaughtered at 4, 5, 6 and 7 months of age. All gilts were bled from indwelling cannulas at 20-min intervals for 4 h the day preceding slaughter. In addition, blood samples were drawn weekly from 17 gilts in each group from 7 to 9 months of age and analysed for progesterone to determine age of puberty. Twelve of 17 gilts that received supplemental lighting reached puberty at 228 (s.e. 11) days of age whereas 11 of 16 gilts that received natural lighting reached puberty at 252 (s.e. 7) days of age (P = 0·07). No significant differences occurred in anterior pituitary gland weight or pituitary concentration of LH, mean concentrations of serum LH or number of LH secretory spikes between natural and supplemental-lighted gilts at each month (all P > 005). Concentration of oestradiol-17β and progesterone in follicular fluid was similar between treatment groups within months and follicular size (P > 0·05). Content of GnRH in the stalk-median eminence, preoptic area and hypothalamus proper were also similar between treatment groups (P > 0·05). In summary, supplemental lighting reduced the age of puberty in gilts without a detectable change in pituitary, hypothalamic or ovarian parameters.

SUPPRESSION OF PROGESTERONE SECRETION IN LACTATING RATS BY ADMINISTRATION OF ERGOCORNINE AND THE EFFECT OF PROLACTIN REPLACEMENT

1975 ◽  
Vol 65 (2) ◽  
pp. 155-161 ◽  
Author(s):  
H. TOMOGANE ◽  
K. ÔTA ◽  
A. YOKOYAMA
Keyword(s):  
Milk Production ◽  
Venous Blood ◽  
Experimental Period ◽  
Prolactin Secretion ◽  
Corpora Lutea ◽  
Undetectable Level ◽  
Stage Of Lactation ◽  
Progesterone Secretion ◽  
Treatment Administration ◽  
Very High

SUMMARY In order to assess the stimulatory effect of prolactin on the secretion of progesterone from corpora lutea in lactating rats, ergocornine maleate (ECO; 1 mg/day), an inhibitor of prolactin secretion, was administered subcutaneously on days 6 and 7 of lactation in primiparous rats. By day 8 of lactation, the concentration of progesterone in ovarian venous blood fell to an undetectable level in the ECO-treated animals, while the concentration in the control animals was very high at this stage of lactation. The level of 20α-hydroxypregn-4-en3-one was significantly higher on day 8 of lactation in ECO-treated than in control rats. Lactational dioestrus was interrupted by treatment with ECO and vaginal oestrus appeared 3–4 days after the start of treatment. Administration of ECO caused deleterious depression of milk production and of food intake of mother rats. In the pair-fed control animals, lactation continued almost normally throughout the experimental period. Prolactin (1 mg/day) administered simultaneously with ECO increased progesterone to levels even higher than those in control rats and restored 20α-hydroxypregn-4-en-3-one levels to those of the controls. The effect of the drug on milk production was alleviated. The results strongly suggest that prolactin is the most important factor in maintaining the function of corpora lutea in the lactating rat.

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.

Oxytocin influences preovulatory follicular development and advances ovulation in rats

1991 ◽  
Vol 125 (1) ◽  
pp. 109-112 ◽  
Author(s):  
Gillian Robinson ◽  
John J. Evans
Keyword(s):  
Follicular Development ◽  
Follicular Growth ◽  
Control Groups ◽  
Gonadotropin Secretion ◽  
Progesterone Secretion ◽  
Induced Changes ◽  
And Control ◽  
Indirect Action

Abstract. Oxytocin has been shown to advance gonadotropin secretion in pro-estrus rats. The effects that oxytocin-induced changes have on the ovary were investigated in this study. Oxytocin administered to rats at proestrus 09.00 h, 10.00 h and 11.00 h advanced follicular growth, progesterone secretion, and the time of ovulation. However, both treated and control groups of rats ovulated similar numbers of oocytes and the oocytes released were of similar fertility. Because oxytocin has been shown to induce early LH and FSH release the effects of oxytocin administration on the ovary were possibly an indirect action involving the pituitary. The results of this investigation indicate that exogenous oxytocin alters, the timing but not the fertility of periovulatory events.

scholarly journals The effect of baseline serum luteinizing hormone levels on follicular development, ovulation, conception and pregnancy outcome in infertile patients with polycystic ovarian syndrome

2017 ◽  
Vol 7 (1) ◽  
pp. 318
Author(s):  
Deepa Shanmugham ◽  
R. K. Vidhyalakshmi ◽  
Shivamurthy H. M.
Keyword(s):  
Luteinizing Hormone ◽  
Pregnancy Outcome ◽  
Polycystic Ovarian Syndrome ◽  
Follicular Development ◽  
Baseline Serum ◽  
Serum Luteinizing Hormone ◽  
Serum Lh ◽  
The Mean ◽  
Infertile Patients ◽  
Ovarian Syndrome

Background: Polycystic Ovarian Syndrome (PCOS) is the most common endocrine disorder in infertile women. Raised tonic levels of luteinizing hormone (LH) is one of the main endocrinological disturbances in PCOS patients. Objective of present study was to evaluate the effect of baseline serum luteinizing hormone levels on follicular development, ovulation and conception and pregnancy outcome in infertile patients with PCOS.Methods: This is a prospective study conducted on 50 consecutive infertile patients with PCOS. Baseline Day 2 serum luteinizing hormone concentration was done in selected patients. Ovulation induction was done with clomiphene citrate 100 mg from Day 3 to Day 7 of the cycle. Then patients were monitored for follicular development, ovulation, conception and early pregnancy loss.Results: The mean age of the patients is 25±3.6 yrs. The average duration of infertility is 5.4 yrs (2-10). The mean basal serum LH concentration in patients who ovulated was significantly low (5.6 IU) in comparison with patients who did not ovulate (10.1 IU).  The mean basal serum LH concentration in patients who conceived was 3.9 IU in comparison with patients who did not conceive (5.9 IU) which was statistically significant (p=0.04).  Out of 15 patients who conceived, 3 patients (20%) had early pregnancy loss.Conclusions: Tonic hyper secretion of LH results in premature oocyte maturation, causing the problems with fertilization and miscarriage. Inappropriately raised LH appears to have deleterious effects on the pregnancy outcome.

Effects of unilateral ovariectomy with compensatory hypertrophy on ovarian blood flow, oxygen consumption and progestin secretion in the 16-day pregnant rat

1999 ◽  
Vol 11 (3) ◽  
pp. 153 ◽  
Author(s):  
N. W. Bruce ◽  
H. M. Massa
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Tissue Blood Flow ◽  
Corpora Lutea ◽  
Tissue Mass ◽  
Pregnant Rat ◽  
Unilateral Ovariectomy ◽  
Arterial Blood ◽  
Progesterone Secretion ◽  
Luteal Tissue

Stimulated ovulation with resultant multiple corpora lutea (CL) can result in lower proges-terone levels than expected from the increased luteal tissue mass. Unilateral ovariectomy (ULO) was used to increase CL number in rats and determine whether this would compromise luteal tissue blood flow, oxygen consumption and progestin secretion. All investigations were performed in vivo, using a venous outflow technique on Day 16 of gestation, when progesterone secretion is maximal. ULO, performed before pregnancy, doubled CL number and total CL mass in the remaining ovary of six treated compared to five control rats. Growth of CL was not affected. The rate of ovarian blood flow (µL min−1 mg CL−1) fell to 47% of control levels in ULO animals and progesterone secretion (µg h−1 mg CL−1) to 68%. Secretion of the minor progestin, 20α-hydroxypregn-4-en-one was not affected. Tissue oxygen consumption was maintained despite the reduction in blood flow by an increase in oxygen extraction from arterial blood. These results suggest that overcrowding of CL in ULO-stimulated rat ovaries compromises luteal tissue blood flow and subsequently progesterone secretion.

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