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PubMed2003

The influence of the ovulation rate on ultrasonically determined ovine corpus luteum morphometry and progesterone concentrations in cyclic and early pregnant sheep.

The objective of the present study was to describe morphology and function of the Corpora lutea (CL) during the oestrous cycle and early pregnancy in sheep with different ovulation rates. In total 40 Booroola. Mutton Merino crosses [heterozygous carriers (FecBFec+) and non-carriers (Fec+Fec+) of the Booroola-fecundity gene (FecB)] with ovulation rates 1 to 4 were examined. During the oestrous cycle (n = 20) and the first month of pregnancy (n = 20) blood samples were taken daily (radioimmunoassay of progesterone) and an ultrasonic ovary diagnosis was conducted. The ewes were scanned transrectally with a 7.5 MHz linear probe lying in a dorsal position. During every examination the CL could be detected. The number and the diameter of the CL were documented and the total volume of luteal tissue per ewe was calculated. The effect of the ovulation rate on CL-morphology (diameter and total volume of luteal tissue per ewe) and peripheral progesterone concentrations were assessed by one-way ANOVA. On day 6 and 7 post ovulationem in cyclic and early pregnant sheep 42% of the diagnosed CL had a cavity. On day 11 (cyclic sheep) and day 10 post ovulationem (early pregnant sheep) this number decreased to 22% (p < 0.05). Both conditions of the CL (compact or with a central cavity) are similar in function and should be regarded as appearances of the same basic process. From the third day onwards the ovulation rate influenced significantly (p < 0.05) the development of the outside diameters of the CL. However, the ovulation rate had no effect on the total volume of the luteal tissue per sheep and on the progesterone concentrations. Yet, in sheep with the ovulation rate 1 significantly lower progesterone concentrations were determined than in sheep with the ovulation rates 2 to 4. In sheep with the ovulation rates 2 to 4 the peripheral progesterone concentrations did not differ significantly. In cyclic and pregnant sheep there is a positive correlation (r = 0.75, p < 0.05) between the progesterone concentration and the total volume of luteal tissue. Considering the smaller diameters of the preovulatory follicles it seems that the development of the CL continues until a threshold-value of progesterone and/or of the total luteal tissue is exceeded. Ewes with low ovulation rates reach this threshold-value with only a few but large CL. With increasing ovulation rate the CL tend to have smaller diameters.

Animals↗
PubMed1994

The temporal relation between the urine LH surge and sonographic evidence of ovulation: determinants and clinical significance.

OBJECTIVES: 1) To define the temporal relation between self-detection of the urine LH surge and sonographic evidence of ovulation, 2) to identify clinical factors that affect this interval, and 3) to determine whether differences in the day of sonographic detection of ovulation could potentially influence pregnancy rates during timed supracervical insemination cycles. METHODS: Two hundred sixty-nine cycles in 145 women treated in an infertility center were analyzed. The subjects were referred for urine LH-timed supracervical insemination and were managed prospectively by protocol, including transvaginal sonographic confirmation of ovulation. Unstimulated and clomiphene citrate cycles were studied. RESULTS: Sonographic evidence of ovulation was detected by the first day after the urine LH surge (day +1) in 95 cycles (35%, 95% confidence interval [CI] 29-41) and not until day +2 in 165 cycles (61%, 95% CI 55-67). Further analyses indicated that cycles with two or more ovulations were associated with a significantly greater percentage of cases in which ovulation was not demonstrated until day +2 (81%, 95% CI 76-86) compared with mono-ovulatory cycles (52%, 95% CI 46-58) (P < .001). Multivariate analysis revealed that the day of sonographic detection of ovulation was linked with clinical pregnancy rates during these insemination cycles (P < .05). CONCLUSIONS: A substantial number of women, especially those with multiple ovulations, will not demonstrate sonographic evidence of ovulation until the second morning after detection of the urine LH surge. This temporal relation may exert an impact on pregnancy rates during supracervical insemination cycles.

Adult↗
PubMed1983

Effect of reproductive status on twinning and on side of ovulation and embryo attachment in mares.

Brood-farm records were used to test several hypotheses concerning twinning and inequalities in the side of ovulation and embryo attachment. Ovulation occurred more frequently (P<0.05) from the left ovary (61% versus 39%) in maiden mares, but with equal frequency from either ovary in lactating and barren mares. The embryo attached more often (P<0.05) to the left horn in lactating mares (60%) and to the right horn in barren (59%) and maiden (67%) mares. Double ovulations and twin embryos were diagnosed more frequently (P<0.05) in barren mares (11% and 6%, respectively) than in lactating mares (5% and 1%). Pregnancy rates for double ovulations were affected (P<0.01) by the length of the interval between the two ovulations (0 days, 83%; 2 days, 87%; 4 days, 67%; 6 days, 54%; 8 days or more, 38%). Pregnancy rates were higher (P<0.01) for double ovulations 0 or 2 days apart (84%) than for single ovulations (54%). Twins were diagnosed more frequently (P<0.05) when double ovulations were two or more days apart (9 32 ) than when the ovulations were synchronous (0 19 ). These results support the conclusion that an embryo-reduction mechanism exists in mares for the elimination of excess embryos and indicate that the mechanism loses its effectiveness when the embryos originate from asynchronous ovulations.

Journal Article↗
PubMed1993

Effects of work and diet on progesterone secretion, short luteal phases and ovulations without estrus in postpartum F1 crossbred dairy cows.

The effects of work and diet supplementation on progesterone secretion and on incidence of short luteal phases and ovulations without estrus was investigated in 40 postpartum F(1) crossbred dairy cows. These cows were allocated to 1 of 4 treatment groups: Group SPNW, supplement-nonworking; Group SPW, supplement-working; Group NSNW, nonsupplement-nonworking; and Group NSW, nonsupplement-working. After calving, working cows pulled sledges with a load of 300 to 450 Newtons(N); 4 hours per day 4 days per week, for a total of 100 days over a 1-year period. All cows were fed natural grass hay ad libitum while the supplemented cows were fed 3 kg of concentrate per head per day. The proportion of cows which showed behavioral estrus by 1 year post partum was 100, 100, 60 and 20% for Group SPNW, SPW, NSNW and NSW cows, respectively. Based on plasma progesterone concentrations, ovulation started 62 days earlier than onset of behavioral estrus. A total of 73 ovulations occurred by 1 year post partum. Forty-nine (67.1%) and 26 (32.9%) ovulations occurred in the supplemented and nonsupplemented cows while 33 (45.2%) and 40 (54.8%) ovulations occurred in the working and nonworking cows, respectively. Of the total ovulations, 26 (35.6%) were not associated with behavioral signs of estrus and occurred in 13 (32.5%) cows. The incidence of ovulation without estrus was higher (P<0.05) in working (42.4%) than in nonworking (30%) cows and in nonsupplemented (41.7%) than in supplemented (32.7%) cows. Short luteal phases occurred in 32.5% of the cows before the establishment of normal estrous cycles. In working cows, diet supplementation off-set the negative effect of work on the onset of estrus and conception. However, a relatively higher number of cows in Group SPW had ovulations without estrus before a normal estrous cycle was established. The incidence of short luteal phases or ovulations without estrus did not influence the pregnancy rate in subsequent normal estrus periods. In conclusion, in the supplemented cows, work did not influence the proportion of cows showing estrus and conceiving, but it significantly delayed the postpartum anestrus interval. In the nonsupplemented cows, reproductive activity was impaired in both working and nonworking cows, but was pronounced in working cows. However, once pregnancy was established there was no effect of work on the maintenance of pregnancy. Our study shows that with appropriate feeding regimens lactating crossbred cows could be used for draught purposes without any detrimental effects on fertility, but calving intervals would be extended. Finally, the physiological mechanisms involved in anestrus and ovulations without estrus and the significance of such phenomena in affecting postpartum reproductive performance and fertility in working cows require further investigation.

Journal Article↗
PubMed1997

The influence of time of insemination relative to time of ovulation on farrowing frequency and litter size in sows, as investigated by ultrasonography.

The objective of this experiment was to identify the optimal time of insemination relative to the time of ovulation, based on ultrasonographic detection of embryonic survival at 10 days after ovulation, number of sows farrowing, and litter size. Furthermore, the possible value of the interval from weaning to onset of estrus for prediction of the time of ovulation was examined. Crossbred sows (n = 143) that had farrowed 2 to 9 litters were weaned (Day 0) and observed for estrus every 8 h from Day 3 until end of estrus. Ultrasonography was performed every 6 h, from 12 h after onset of estrus until ovulation had been observed. The sows were inseminated once at various time intervals from ovulation. At Day 16, 25 of the sows were slaughtered and their uteri were flushed for embryos. In the remaining sows, the number of viable and dead piglets and mummified fetuses per sow was recorded at farrowing, with the sum of the 3 constituting the total number of piglets born per sow. The highest number of embryos recovered per sow was found after insemination during the interval from 24 h before to 4 h after ovulation. The lowest frequency of non-pregnant sows and the highest total number of piglets born per sow were found after insemination from 28 h before to 4 h after ovulation. Consequently, the optimal time for insemination was found to be in the interval 28 h before to 4 h after ovulation. The interval from weaning to onset of estrus and from onset of estrus to ovulation were negatively correlated, allowing a rough prediction of the time of ovulation from the interval from weaning to onset of estrus.

Journal Article↗
PubMed2004

Pollen histochemistry and pollen : ovule ratios in Zingiberaceae.

BACKGROUND AND AIMS: Pollen grains of 37 species from 11 genera in the family Zingiberaceae were examined to assess qualitatively starch or lipid contents; the pollen grain and ovule numbers per flower and pollen : ovule ratios were also counted and calculated. Pollen : ovule ratios were studied to reveal patterns of variation in the Zingiberaceae. METHODS: Freshly open flowers with dehiscing anthers were collected at random from plants growing in natural habitats or in botanical gardens. Presence of lipids or starch in pollen grains was tested by Sudan solution and IKI solution, respectively, and examined under a microscope. To estimate the pollen and ovule numbers per flower, one anther from each bud was carefully dissected and all pollen grains were counted; ovaries were carefully dissected out of each flower and counted. Whenever possible, at least 10-15 buds were used in the determination. KEY RESULTS: Thirty-three of all the 37 species examined had starchy pollen. Starch was not found in only four species and lipid was not found in only one species; among the four tribes in subfamily Zingiberoideae, all species of Zingibereae and Globbeae had pollen with no starch, Alpineae and Hedychieae had pollen with and without starch, whereas, all species of subfamily Costoideae had starchy pollen with abundant lipids. The mean pollen : ovule ratios in the members of the Zingiberaceae investigated range from 3.25 +/- 1.56 to 616.52 +/- 117.83. CONCLUSIONS: The pollen nutrition types seemed not related to mating systems. The pollen : ovule ratios in members of the Zingiberaceae with the same breeding system are noticeably lower than those recorded by previous authors. The lower pollen : ovule ratios in this family are presumed to be related to the highly efficient pollination systems, mediated by pollen which can be quite glutinous and the relatively large stigma area. In most of the Alpinia species the anaflexistylous flowers have much larger numbers of pollen grains and higher pollen : ovule ratios than the cataflexistylous flowers. There are significant differences in mean pollen grain numbers and pollen : ovule ratios between different life forms but ovule numbers are approximately the same.

Flowers↗
PubMed2001

Development of sterile ovules on bisexual cones of Gnetum gnemon (Gnetaceae).

Angiosperms and Gnetales (Ephedra, Gnetum, Welwitschia) represent the only seed plants that regularly produce bisexual cones. Unfortunately, the fertility and function of ovules formed on bisexual cones of Gnetales have remained unclear. Some reports indicate that the ovules are sterile while others indicate that they may develop into seeds. This study demonstrates three different developmental patterns of ovules formed on bisexual cones of Gnetum gnemon. Type I ovules did not develop at all after pollination and represented the majority of ovules on each cone. Type II ovules enlarged slightly after pollination due to the enlargement of nucellar tissue. Type III ovules were typically found on the terminal whorl and developed into seed-like structures. The enlargement was due to proliferation of megagametophyte tissue. Sectioned material revealed that megagametophytes show altered development compared to those found in functional female ovules. None of the ovules studied contained embryos, and thus all were sterile. Densitometry of 4',6-diamidino-2-phenylindole (DAPI)- stained sections revealed that megagametophyte nuclei formed in the sterile ovules are unreduced (diploid) and thus do not form viable female gametes.

Journal Article↗
PubMed2005

Does injection of prostaglandin F(2alpha) (PGF2alpha) cause ovulation in anestrous Western White Face ewes?

In a previous study in our laboratory, treatment of non-prolific Western White Face (WWF) ewes with PGF(2 alpha) and intravaginal sponges containing medroxyprogesterone acetate (MAP) on approximately Day 8 of a cycle (Day 0 = first ovulation of the interovulatory interval) resulted in ovulations during the subsequent 6 days when MAP sponges were in place. Two experiments were performed on WWF ewes during anestrus to allow us to independently examine if such ovulations were due to the direct effects of PGF(2 alpha) on the ovary or to the effects of a rapid decrease in serum concentrations of progesterone at PGF(2 alpha)-induced luteolysis. Experiment 1: ewes fitted with MAP sponges for 6 days (n = 12) were injected with PGF(2 alpha) (n = 6; 15 mg im), or saline (n = 6) on the day of sponge insertion. Experiment 2: ewes received progesterone-releasing subcutaneous implants (n = 6) or empty implants (n = 5) for 5 days. Six hours prior to implant removal, all ewes received a MAP sponge, which remained in place for 6 days. Ewes from both experiments underwent ovarian ultrasonography and blood sampling once daily for 6 days before and twice daily for 6 days after sponge insertion. Additional blood samples were collected every 4 h during sponge treatment. Experiment 1: 4-6 (67%) PGF(2 alpha)-treated ewes ovulated approximately 1.5 days after PGF(2 alpha) injection; these ovulations were not preceded by estrus or a preovulatory surge release of LH, and resulted in transient corpora hemorrhagica (CH). The growth phase was longer (P < 0.05) and the growth rate slower (P < 0.05) in ovulating versus non-ovulating follicles in PGF(2 alpha)-treated ewes. Experiment 2: in ewes given progesterone implants, serum progesterone concentrations reached a peak (1.7 2 ng/mL; P < 0.001) on the day of implant removal and decreased to basal concentrations (<0.17 ng/mL; P < 0.001) within 24 h of implant removal. No ovulations occurred in either the treated or the control ewes. We concluded that ovulations occurring after PGF(2 alpha) injection, in the presence of a MAP sponge, could be due to a direct effect of PGF(2 alpha) at the ovarian level, rather than a sudden decline in circulating progesterone concentrations.

Anestrus↗
PubMed2002

Ovarian steroidogenesis in white sturgeon (Acipenser transmontanus) during oocyte maturation and induced ovulation.

Ovarian follicles and plasma were collected from two female white sturgeon, Acipenser transmontanus, injected with sturgeon pituitary homogenate followed 12h later with GnRHa to induce ovulation. The oocytes of one female underwent germinal vesicle breakdown (GVBD) but ovulation did not occur in response to hormonal stimulation (Female 1), while the oocytes of the other female underwent GVBD and ovulation (Female 2). Follicles collected 12h after the first injection to induce ovulation were incubated with radioinert pregnenolone (P5) or tritiated-P5 ([3H]P5) plus radioinert P5. Steroids were extracted from media and intact follicles, and the extracts were fractionated by high performance liquid chromatography (HPLC). Fractions from the incubation with radioinert precursor were used in a bioassay to determine the potency of the steroid products to induce GVBD. Plasma levels of testosterone (T), estradiol, and 17,20beta-dihydroxy-4-pregnen-3-one (17,20beta-P) were measured by radioimmunoassay during induced ovulation, and plasma collected at the time of ovulation (actual or expected) was analyzed by HPLC. A peak in plasma 17,20beta-P was detected at the time of the second injection to induce ovulation in Female 2 (the time at which follicles were collected for incubation with [3H]P5). The HPLC analysis revealed several progestins in the plasma of Female 2 at ovulation that were not present in Female 1 at the time of expected ovulation. A variety of C19 and C21 steroids were produced in vitro by ovarian follicles from both females. The "suggestive" identities of the major metabolites were 11-deoxycortisol, androstenedione, 17-hydroxyprogesterone (17OHP), and 17,20beta-P in Female 1 and cortisol, 17,20beta, 21-trihydroxyprogesterone (20beta-S), 11-deoxycortisol, T, 17OHP, and 17,20beta-P in Female 2. Several of the steroids were active in a GVBD bioassay, but the fractions that contained the steroid coeluting the authentic 11-deoxycortisol on the HPLC and 17,20beta-P (positively identified by gas chromatography-mass spectrometry) were found to be the most potent. The results from this study combined with the results of Webb et al. (2001b) suggest the potential roles of 11-deoxycortisol, 17,20beta-P, 20beta-S, and P4 as maturation-inducing steroids in sturgeon.

Animals↗
PubMed1999

Synchronization rate, size of the ovulatory follicle, and pregnancy rate after synchronization of ovulation beginning on different days of the estrous cycle in lactating dairy cows.

Recently a protocol was developed that precisely synchronizes the time of ovulation in lactating dairy cows (Ovsynch; GnRH-7d-PGF2 alpha-2d-GnRH). We evaluated whether initiation of Ovsynch on different days of the estrous cycle altered the effectiveness of this protocol. The percentage of cows (n = 156) ovulating to the first GnRH was 64% and varied (P < 0.01) by stage of estrous cycle. Treatment with PGF2 alpha was effective, with 93% of cows having low progesterone at second GnRH. The overall percentage of cows that ovulated after second GnRH (synchronization rate) was 87% and varied by response to first GnRH (92% if ovulation to first GnRH vs 79% if no ovulation; P < 0.05). There were 6% of cows that ovulated before the second injection of GnRH and 7% with no detectable ovulation by 48 h after second GnRH. Maximal diameter of the ovulatory follicle varied by stage of estrous cycle, with cows in which Ovsynch was initiated at midcycle having the smallest follicles. In addition, milk production and serum progesterone concentration on the day of PGF2 alpha affected (P < 0.05) size of the ovulatory follicle. Using these results we analyzed pregnancy rate at Days 28 and 98 after AI for cows (n = 404) in which Ovsynch was initiated on known days of the estrous cycle. Pregnancy rate was lower for cows expected to ovulate larger follicles than those expected to ovulate smaller follicles (P < 0.05; 32 vs 42%). Thus, although overall synchronization rate with Ovsynch was above 85%, there were clear differences in response according to day of protocol initiation. Cows in which Ovsynch was initiated near midcycle had smaller ovulatory follicles and greater pregnancy rates.

Animals↗
PubMed1988

Outcome of pregnancy in underweight women after spontaneous and induced ovulation.

Low maternal weight before pregnancy and poor weight gain during pregnancy are known to result in an increased prevalence of low birthweight infants. Low body weight is also an important cause of amenorrhoea. The hypothesis that amenorrhoeic underweight women who become pregnant after induction of ovulation are more at risk of delivering low birthweight infants than underweight women who ovulate spontaneously was investigated. Forty one pregnant women in whom ovulation had been induced and 1212 in whom ovulation was spontaneous were studied. Women ovulating spontaneously whose weight was normal and who showed good weight gain during pregnancy (greater than 450 g a week) had the lowest incidence (6%) of babies who were small for gestational age. Underweight women (body mass index less than 19.1) who ovulated spontaneously had a threefold increased risk of delivering babies who were small for gestational age (18%). Overall, the women in whom ovulation had been induced had an even higher risk of babies who were small for dates (25%), and the risk was greatest (54%) in those who were underweight. The outcome of pregnancy is related to weight before conception, which in many cases reflects nutritional state; lack of spontaneous ovulation indicates an increased risk of producing a small for dates infant. The most suitable treatment for infertility secondary to weight related amenorrhoea is therefore dietary rather than induction of ovulation.

Body Weight↗
PubMed1990

Use of gonadotropin-releasing hormone for hastening ovulation in transitional mares.

Natural GnRH and its analog have potential for hastening ovulation in mares. A study was conducted to evaluate the efficacy of a GnRH agonist given either as an injectable or s.c. implant for induction of ovulation in mares. Forty-five seasonally anestrous mares (March) were assigned to one of three groups (n = 15/group): 1) untreated controls; 2) i.m. injection of the GnRH agonist buserelin at 12-h intervals (40 micrograms/injection for 28 d or until ovulation) and 3) GnRH agonist administered as a s.c. implant (approximately 100 micrograms/24 h for 28 d). Six mares per group were bled on d 0, 7, 14 and 21 after injection or insertion of implant. Samples were taken at -1, -.5 and 0 h and at .5, 1, 1.5, 2, 4, 6 and 8 h after GnRH. Additional daily samples were drawn for 28 d after injection or until ovulation. Samples were assayed for concentration of LH and FSH. Progesterone concentrations were determined in samples collected on d 4, 6 and 10 after ovulation. Number and size of follicles and detection of ovulation were determined by ultrasonography. Number of mares induced to ovulate within 30 d was 0 of 15, 7 of 15 and 9 of 15 for groups 1, 2 and 3, respectively. During treatment, follicle sizes were smaller for mares in group 3 (implant). The LH response to GnRH agonist (area under curve) was similar among groups at d 0 but was greater (P less than .05) for mares in group 3 on d 7 and 14 and groups 2 and 3 on d 21 than for controls. A similar pattern was detected for peak concentrations of LH after GnRH on d 0, 7, 14 and 21. Daily concentrations of LH remained low in untreated control mares compared with GnRH-treated mares throughout the sampling period. Concentrations of LH for mares in group 3 that ovulated were elevated greatly above those for group 2 mares, whereas concentrations of FSH were similar in both treatment groups prior to ovulation.

Anestrus↗
PubMed1998

Ultrasonic evaluation for the time of ovulation in ewes treated with norgestomet and norgestomet followed by pregnant mare's serum gonadotropin.

Progestogens and follicular stimulants have proved reasonably successful for estrus synchronization, but time of ovulation relative to removal of the progestogen is not clearly established. We monitored time of ovulation in ewes following synchronized estrus. Ovaries of 40 Dorset and Rambouillet x Dorset ewes were evaluated during the spring and fall (20/replicate). Ewes were randomly assigned to one of two treatment groups (n = 20/group): implant-only (I) ewes received a norgestomet implant for 10 d; and implant + PMSG (PI) ewes received a norgestomet implant for 10 d with an i.m. injection of 500 IU of PMSG at implant removal. Time of estrus onset was detected with the HeatWatch Estrus Detection System. Following the initiation of estrus, ovaries were monitored via rectal ultrasonography every 6 h to determine the interval from implant removal to ovulation (OVUL), and onset of estrus to ovulation (INT). Four I and PI ewes that lost implants before scheduled removal on d 10 were removed from the study. Estrus was detected in 13 of 16 (81%) I and 14 of 16 (88%) PI ewes within 108 h after implant removal. The interval from implant removal to estrus (EST), INT, and OVUL were not affected by replicate. The INT was not different in I (33.8 h) and PI (35.0 h) ewes. Mean OVUL was greater (P < .01) in I (79.8 h) than in PI ewes (68.6 h), and mean EST was also greater (P < .01) for I (46.0 h) than for PI ewes (32.6 h). The present data indicate that ovulation occurs on average 70 to 80 h after implant removal in ewes treated with norgestomet, and PMSG reduces the interval from implant removal to ovulation.

Animals↗
PubMed1995

Follicular development and ovulation in sows: effect of hCG and GnRH treatment.

Follicular growth, chronology of ovulation and embryo morphology were compared in sows ovulating spontaneously and sows, in which the ovulation was attempted induced by hCG or GnRH. Indwelling catheters were placed on day 1 (weaning = day 0) in the ear veins of 18 sows, which were then randomly divided into 3 groups: a control group (N = 6), a group (N = 6) given 750 iu hCG (Physex) im 76h after weaning (hCG group) and a group (N = 6) given 500 micrograms GnRH (Fertagyl) im 76h (N = 3) or 100h after weaning (N = 3) (GnRH group). Follicular diameter and time of ovulation were monitored by ultrasonography every 4h from day 3 until ovulation or development of cysts by means of a sector scanner fitted with a 5.0/7.5 MHz multiangle probe. Heat detection was performed every 8h from day 3 until ovulation. On day 13, the sows were slaughtered, the number of corpora luteae (CL) was counted, and embryos were flushed from the uteri. The control group showed clear heat symptoms, and on day 3, the follicles were typically 3-7 mm and grew up to 7-10 mm over 2 days, where they remained for approximately 24h until ovulation took place 41h +/- 9h after first sign of standing heat. The hCG group exhibited no signs of heat, and the follicles only reached 5-8 mm in diameter at time of ovulation, which occurred 40h +/- 1h after hCG-injection. The GnRH group exhibited inconsistent signs of heat, and the follicles reached a maximum size of 7-12 mm in diameter where they remained for more than 24h. Only 2 sows in this group ovulated within 84-92h after the GnRH injection, and development of bursa cysts and cystic follicles was a common finding. The average number of CL was 18.2 +/- 5.7 per sow (N = 16, range: 3-27) with no significant difference between the groups. Total embryo recovery was 79 +/- 13% with no significant difference between groups. The embryo diversity calculated as standard deviation of the maximum diameter was higher in the hCG group as compared with the control group.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2005

Laparoscopic "drilling" by diathermy or laser for ovulation induction in anovulatory polycystic ovary syndrome.

BACKGROUND: Problems in inducing ovulation in women with polycystic ovary syndrome (PCOS) and anovulation (failure to ovulate) are well recognised. Surgical ovarian wedge resection was the first established treatment for anovulatory PCOS patients but was largely abandoned due to the risk of post-surgical adhesions and the introduction of medical ovulation induction with clomiphene and gonadotrophins. However patients with PCOS treated with gonadotrophins often have an over-production of follicles and are exposed to the risks of ovarian hyperstimulation syndrome (OHSS) and multiple pregnancy. Moreover ovulation induction with gonadotrophins, though effective, is an expensive, inconvenient and time-consuming treatment requiring intensive monitoring. Surgical therapy with laparoscopic ovarian "drilling" (LOD) may avoid or reduce the need for gonadotrophins or may facilitate their use. The procedure can be done on an outpatient basis with less trauma and fewer postoperative adhesions. Many uncontrolled observational studies have claimed that ovarian drilling is followed, at least temporarily, by a high rate of spontaneous ovulation and conception, and/or that subsequent medical ovulation induction becomes easier. OBJECTIVES: To determine the effectiveness and safety of laparoscopic ovarian drilling compared with ovulation induction for subfertile women with clomiphene-resistant PCOS. SEARCH STRATEGY: We used the search strategy of the Menstrual Disorders and Subfertility Group. SELECTION CRITERIA: We included randomised controlled trials of subfertile women with clomiphene-resistant PCOS that undertook laparoscopic ovarian drilling in order to induce ovulation. DATA COLLECTION AND ANALYSIS: Fifteen trials were identified and six were included in the review. All trials were assessed for quality criteria. The primary outcomes were live birth, ovulation and pregnancy rates and the secondary outcomes were rates of miscarriage, multiple pregnancy, ovarian hyperstimulation syndrome and cost. MAIN RESULTS: There was no evidence of a difference in live births or ongoing pregnancies between LOD and gonadotrophins and the pooled Odds Ratio (OR) (all studies) was 1.04 (95% CI 0.74, 1.99) and 1.16 (95% CI 0.72, 1.86) respectively. Multiple pregnancy rates were lower with ovarian drilling than with gonadotrophins (1% vs 16%, OR: 0.13, 95% CI: 0.03 to 0.59). There was no evidence of a difference in miscarriage rates between the two groups (OR 0.81, 955% 0.36, 1.86). AUTHORS' CONCLUSIONS: There was no evidence of a difference in the live birth rate and miscarriage rate in women with clomiphene resistant PCOS undergoing LOD compared to gonadotrophin treatment. The reduction in multiple pregnancy rates in women undergoing LOD makes this option attractive. However, there are ongoing concerns about long term effects of LOD on ovarian function.

Anovulation↗
PubMed1984

Regulation of the follicular hierarchy and ovulation.

Studies are discussed which investigate the regulation of follicular maturation and the ovulation sequence of the domestic hen. The number of FSH receptors of ovarian granulosa cells decreases as the follicle matures, and this decrease in receptor number is paralleled by a gradual loss of FSH-stimulable adenylyl cyclase (AC) activity. By contrast, LH-stimulable AC activity increases as the follicle progresses through the hierarchy. In addition, FSH stimulates progesterone secretion by granulosa cells of the smaller preovulatory follicles, whereas these cells are only minimally responsive to LH. These data suggest that the maturation of less mature (smaller) follicles is primarily controlled by FSH, while LH may serve primarily as the ovulation-inducing hormone. The ability of LH to stimulate progesterone release and induce premature ovulation is dependent upon the stage of the sequence. Injection of ovine LH 12 hr prior to ovulation of the first (C1) egg of the sequence induces fully potentiated preovulatory plasma progesterone surges and 100% premature ovulation, whereas injection prior to the second (C2) ovulation of the sequence fails to stimulate prolonged progesterone release and induces premature ovulation in less than 50% of injected hens. These results are consistent with data obtained in vitro which suggest that granulosa cells obtained 12 hr prior to a C1 ovulation secrete more progesterone in response to chicken LH compared to those obtained 12 hr prior to the C2 ovulation. These data are discussed in terms of the ovary's ability to act as a regulator of the ovulatory cycle.

Adenylyl Cyclases↗
PubMed1994

Modulation of spermatozoa and zona pellucida properties by the soluble acrosome reaction-inducing factor of the ovulated egg-cumulus complex.

Three sources of hamster periovulatory fluids (+/- heat inactivation at 56 degrees C), with bovine serum albumin (BSA) as control, were tested for effects on penetration of three classes of eggs by hamster sperm precapacitated in BSA. These fluids were a soluble extract of cumulus oophorus fluid (COF) from the ovulated hamster egg-cumulus complex, serum, and follicular fluid. Egg types were ovulated, salt-stored (ovulated), and follicular. In both COF and serum, there were significant differences among egg types in mean penetration, and significant effects of fluid addition. In contrast, there was no effect of follicular fluid and no differences between follicular and stored eggs. For the follicular eggs (combined data, normalized, ranked), patterns of response to the three factors (+/- heating) were different: only unheated COF and heated serum increased penetration significantly above BSA control levels (average rank 20.2, 41.4, 38, for BSA, COF (unheated), serum (heated), respectively). This indicated that the active component in COF was heat labile, not present in either serum or follicular fluid, and, therefore, of oviductal origin. Oviduct and/or COF exposure of eggs and sperm was tested for effects as an acrosome reaction inducing factor (ARIF) for acrosome reactions (AR; zona-bound and free-swimming sperm) and on sperm:zona binding and penetration. The COF ARIF for free-swimming sperm AR was heat stable. Penetration of follicular eggs increased after incubation in COF prior to sperm addition, but a greater response occurred when COF was added to eggs with sperm. In kinetic experiments, 25 min following sperm attachment, follicular eggs had lost 41% of initially bound sperm, vs. 23% for ovulated eggs, and had only 16 AR sperm/egg, vs. 26 for ovulated. Follicular eggs incubated in COF (then washed three times) had the same number of bound AR sperm as ovulated eggs. Acid solubilized zona pellucida (ASZP) from ovulated eggs was more effective as an ARIF per zona than ASZP from follicular eggs. Zonae of follicular eggs, as evidenced by dissolution times in beta-mercaptoethanol (beta-MEOH), were not "harder" than those of ovulated eggs. There were differences in lectin binding antigens on zonae of both fresh and stored, follicular and ovulated, eggs. We conclude that multiple biological factors orchestrate sperm:egg interactions in the ampulla. Our data are consistent with the presence of at least three effective components: 1) the oviductal lectin-binding antigen (ZPO or oviductin), 2) an additional heat-labile component, and 3) the heat-stable ARIF for free-swimming sperm.

Animals↗
PubMed1990

Ovulation blockade through synergism of cycloheximide with assorted anesthetics.

This report addresses the following question: Can ovulation be blocked through a combined action of two drugs, which individually have no effect on ovulation. Ovulation blockade in hamsters was achieved through synergism of two drugs that individually had no effect on ovulation. Treatments were given at 18:00 h on pro-estrus. The keystone finding was that cycloheximide (CX), in a dose too small to affect ovulation, can be made to block ovulation by pretreating hamsters 15 min earlier with pentobarbital. Ovulation blockade was also achieved with phenobarbital + CX, ketamine + CX, and ether + CX. When given alone, none of the four anesthetics interfered with ovulation. The mechanism by which the anesthetic/CX synergism works is not known. The pituitary can be excluded as a target, because it is not necessary for ovulation after 15:30 on pro-estrus. It is speculated that CX reduces the synthesis of ovarian proteins needed for follicle rupture, and the anesthetics augment this process through action on either the ovary, the brain, the liver, or a combination thereof.

Anesthetics↗