PMID: 2123497Nov 1, 1990Paper

The antagonistic effect of exogenous LH pulses on FSH-stimulated preovulatory follicle growth in ewes chronically treated with a gonadotrophin-releasing hormone agonist

The Journal of Endocrinology
H M PictonA S McNeilly

Abstract

The hypogonadotrophism model induced by the chronic administration of gonadotrophin-releasing hormone (GnRH) agonist was used to investigate the effects of different concentrations of FSH with or without LH pulses on the stimulation of follicular development in the ewe. Continuous administration of an agonist (buserelin) by osmotic minipump to thirty-six Welsh Mountain ewes from the early luteal phase for 5 weeks resulted in a sustained suppression of the plasma concentration of FSH and inhibited the pulsatile release of LH. The inhibition of gonadotrophin secretion was due to the desensitization and/or down-regulation of pituitary gonadotroph function, since the agonist-treated animals showed no response to a challenge of 1 microgram GnRH. During week 6 of agonist treatment, ewes were infused with either 4-hourly pulses of ovine LH (9 micrograms/pulse), low concentrations of ovine FSH (3 micrograms/h) or high concentrations of FSH (9 micrograms/h) alone or with 4-hourly pulses of LH. After 5 days of gonadotrophin infusion, there was no difference between the mean number of follicles per ewe from the animals treated with LH alone, low concentrations of FSH with or without LH pulses or the high concentration of FSH alone compare...Continue Reading

Citations

Jan 1, 1991·The Journal of Steroid Biochemistry and Molecular Biology·A S McNeilly
Jul 30, 2009·Reproductive Biology and Endocrinology : RB&E·Srinivas V SeekalluNorman C Rawlings
Sep 1, 1990·Baillière's Clinical Obstetrics and Gynaecology·D T BairdA F Glasier
Oct 28, 2019·Reproduction, Fertility, and Development·Jin G GongRobert Webb

❮ Previous
Next ❯

Related Concepts

Related Feeds

CZI Human Cell Atlas Seed Network

The aim of the Human Cell Atlas (HCA) is to build reference maps of all human cells in order to enhance our understanding of health and disease. The Seed Networks for the HCA project aims to bring together collaborators with different areas of expertise in order to facilitate the development of the HCA. Find the latest research from members of the HCA Seed Networks here.