Search Results
Department of Reproduction and Infertility, Chengdu Women’s and Children’s Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, China
Search for other papers by Ling Cui in
Google Scholar
PubMed
Search for other papers by Chunlu Tan in
Google Scholar
PubMed
Search for other papers by Lili Huang in
Google Scholar
PubMed
Search for other papers by Weihao Wang in
Google Scholar
PubMed
Search for other papers by Zhengxiang Huang in
Google Scholar
PubMed
Search for other papers by Fang Geng in
Google Scholar
PubMed
Search for other papers by Mengjun Wu in
Google Scholar
PubMed
Search for other papers by Xiaolin Chen in
Google Scholar
PubMed
Search for other papers by Michael Cowley in
Google Scholar
PubMed
Search for other papers by Ferdinand Roelfsema in
Google Scholar
PubMed
Search for other papers by Chen Chen in
Google Scholar
PubMed
–melanocortin receptor (melanocortin 4 receptor, MC4R) signaling led to hyperphagia and obesity ( Vaisse et al. 2000 ). MC4R KO mouse line was reported to have irregular reproductive cycles and fewer ovulations ( Sandrock et al. 2009 ). Reproductive hormone
Centre for Neurobiochemical Studies on Endocrine Diseases, Laboratory of Neurobiochemistry, Department of Biochemistry and Molecular Biology, Faculty of Chemistry and Pharmaceutical Sciences, Universidad de Chile, Santiago de Chile, Chile
Search for other papers by Miguel del Campo in
Google Scholar
PubMed
Search for other papers by Néstor Lagos in
Google Scholar
PubMed
Search for other papers by Hernán Lara in
Google Scholar
PubMed
Introduction High testosterone plasma levels and the presence of fluid-filled follicles (cysts) that do not ovulate characterize polycystic ovary syndrome (PCOS). PCOS is the most prevalent ovarian pathology in women, affecting 5–12% of women
Search for other papers by Tony M Plant in
Google Scholar
PubMed
evidence upon which Harris' hypothesis was based had been obtained primarily from studies of the female, most likely because ovulation was a discrete and readily detected event and, at the time, the only reliable surrogate marker of acute hypothalamic
Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
Search for other papers by A Hourvitz in
Google Scholar
PubMed
Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
Search for other papers by E Gershon in
Google Scholar
PubMed
Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
Search for other papers by J D Hennebold in
Google Scholar
PubMed
Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
Search for other papers by S Elizur in
Google Scholar
PubMed
Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
Search for other papers by E Maman in
Google Scholar
PubMed
Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
Search for other papers by C Brendle in
Google Scholar
PubMed
Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
Search for other papers by E Y Adashi in
Google Scholar
PubMed
Department of Biological Regulation, Weizmann Institute of Science, Rehovot, Israel
Search for other papers by N Dekel in
Google Scholar
PubMed
Introduction The individual phases of the normal ovarian life cycle are controlled by a highly synchronized and exquisitely timed cascade of gene expression ( Richards 1994 , Richards et al. 1995 ). Ovulation, a complex process
Departments of Animal Science
Physiology
Molecular Reproductive Endocrinology Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
Search for other papers by Qinglei Li in
Google Scholar
PubMed
Departments of Animal Science
Physiology
Molecular Reproductive Endocrinology Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
Search for other papers by Fermin Jimenez-Krassel in
Google Scholar
PubMed
Departments of Animal Science
Physiology
Molecular Reproductive Endocrinology Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
Search for other papers by Anilkumar Bettegowda in
Google Scholar
PubMed
Departments of Animal Science
Physiology
Molecular Reproductive Endocrinology Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
Search for other papers by James J Ireland in
Google Scholar
PubMed
Departments of Animal Science
Physiology
Molecular Reproductive Endocrinology Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
Search for other papers by George W Smith in
Google Scholar
PubMed
Introduction Ovulation, triggered by the preovulatory luteinizing hormone (LH) surge, is a prerequisite for fertilization and embryonic development. Preovulatory degradation of the extracellular matrix at the follicle apex is a
Search for other papers by I. J. CLARKE in
Google Scholar
PubMed
Search for other papers by R. J. SCARAMUZZI in
Google Scholar
PubMed
Search for other papers by R. V. SHORT in
Google Scholar
PubMed
SUMMARY
The ovarian activity of prenatally androgenized ewes was studied by measuring plasma progesterone concentrations in daily samples of peripheral blood, and by examining the ovaries at laparotomy.
Ewes that were exposed to testosterone between days 30 and 80, 50 and 100 or 70 and 120 of foetal life by implanting their mothers with 1 g testosterone, failed to show regular overt oestrous cycles, although some of them ovulated, whereas ewes exposed to testosterone between days 90 and 140 of foetal life had normal oestrous cycles. The incidence of ovulatory failure appeared to increase with age in ewes treated between days 50 and 100 or days 70 and 120 of foetal life.
Search for other papers by D. W. BULLOCK in
Google Scholar
PubMed
Search for other papers by A. V. NALBANDOV in
Google Scholar
PubMed
SUMMARY
The ovarian ascorbic acid-depletion assay has been used to determine the luteinizing hormone (LH) content of plasma at different times in the laying cycle of the hen. The existence of three peaks of LH release preceding ovulation was confirmed and no fourth peak was determined. By injection of an anti-adrenergic drug (dibenzyline) to prevent ovulation, all three releases of LH were inhibited.
Preceding the missed ovulation leading to a pause in the laying cycle, no peaks of plasma LH were found. These results provide direct evidence on which theories for the hen's ovulation cycle can be assessed.
Search for other papers by L. E. ROWSON in
Google Scholar
PubMed
Follicles in relatively large numbers (average 26) have been consistently produced by the injection of 3600 and 4500 i.u. of whole pregnant mares' serum, and to a slightly lesser degree (average 14), by the injection of similar amounts of commercial processed pregnant mares' serum.
Ovulation after this treatment has been spontaneous, but to a lesser degree when using the processed material (5·4% ovulations) than when using the whole plasma (24% ovulations).
The percentage of ovulations after this treatment has been increased by the intravenous injection of chorionic gonadotrophin at a dosage of 2000 i.u. (22% for processed material and 42% for whole serum). Where a large corpus luteum was present in the ovary during the time of treatment, the percentage ovulations was 52 as compared with only 14 in those cases in which no corpus luteum was present.
Injections of 20 mg. progesterone daily for 4 days after removal of the corpus luteum, and after the p.m.s. injections, had the same effect on the ovulation rate (55% ovulations) as the presence of a large corpus luteum.
Ova produced by either processed or whole serum can be fertilized fairly readily in the absence of a corpus luteum, but in its presence or after daily injections of progesterone, no fertilization takes place.
In the presence of a corpus luteum or after injections of progesterone, the ova travel down the Fallopian tube at a greatly increased rate, but were in some cases slowed up by the injection of oestrogens.
Search for other papers by Jennifer H Steel in
Google Scholar
PubMed
Search for other papers by Roger White in
Google Scholar
PubMed
Search for other papers by Malcolm G Parker in
Google Scholar
PubMed
) and energy homeostasis ( Leonardsson et al. 2004 ). This review will focus on the function of RIP140 in the ovary to regulate ovulation and in adipose tissue to regulate fat accumulation. RIP140 binds to nuclear receptors in a ligand
Search for other papers by B. J. WEIR in
Google Scholar
PubMed
SUMMARY
Forty-five adult chinchilla (Chinchilla laniger) were used to investigate the ovulatory response to pregnant mare serum (PMS) and human chorionic gonadotrophin (HCG) administered by intraperitoneal injection according to various regimes. Ovulation occurred (even during pregnancy) only when both PMS and HCG were given; 87·5% animals ovulated with a mean number of 3·7 ova, but only 26 out of the 119 ova were recovered. The range of ova ovulated per ovary was 1–7 and the range per animal was 1–12. The reasons for the low recovery rate of eggs and the general efficacy of the hormone regimes are discussed.
