title: LH secretion and response to GnRH during seasonal anoestrus of the Pére David's deer hind (Elaphurus davidianus).
abstract: The pattern of LH secretion and response to exogenous GnRH was determined on 5 occasions during seasonal anoestrus of the Père David's deer hind. LH pulse frequency was low (3.3 +/- 0.6 pulses/18 h) in early anoestrus (February), increased significantly in mid-anoestrus (April; 8.4 +/- 1.4 pulses/18 h) and thereafter declined slightly in late anoestrus (June; 6.3 +/- 0.25 pulses/18 h). Mean LH concentrations also showed significant changes during anoestrus with higher levels in mid-anoestrus (April; 0.85 +/- 0.12 ng/ml) when compared with other times (0.53 +/- 0.05, 0.60 +/- 0.10, 0.68 +/- 0.06 and 0.71 +/- 0.05 ng/ml for February, March, May and June, respectively). LH pulse amplitude showed no significant changes during the study. The LH response to intravenous injections of 2 micrograms GnRH was lowest in early anoestrus (February), increased significantly in mid-anoestrus (April) and remained high through late anoestrus. The response during the luteal phase was similar to that seen during late anoestrus. These results indicate that seasonal anoestrus in the Père David's deer hind is not a uniform state but is characterized by an early period of 'deep' anoestrus.
authors.affiliation: M.R.C./A.F.R.C. Comparative Physiology Research Group, Institute of Zoology, London, UK.
authors.forename: J D
authors.initials: JD
authors.lastname: Curlewis
authors.forename: B J
authors.initials: BJ
authors.lastname: McLeod
authors.forename: A S
authors.initials: AS
authors.lastname: Loudon
mesh_terms: D000780:Anestrus / Q000502:physiology*; D000818:Animals; D003670:Deer / Q000097:blood / Q000502:physiology; D005260:Female; D008183:Luteal Phase / Q000502:physiology; D007986:Luteinizing Hormone / Q000097:blood / Q000378:metabolism*; D010906:Pituitary Hormone-Releasing Hormones / Q000494:pharmacology*; D012621:Seasons; D012636:Secretory Rate / Q000187:drug effects
chemical_list: D010906:Pituitary Hormone-Releasing Hormones; D007986:Luteinizing Hormone