title: Termination of obligate anoestrus and induction of fertile ovarian cycles in dogs by administration of purified pig LH.
abstract: The potential role of LH in the initiation of the follicular phase in dogs was investigated by treating anoestrous bitches with highly purified pig LH (n = 16) or saline (n = 8) three times a day for 7 days, beginning in either early anoestrus (days 94-116 of the cycle) or mid-anoestrus (days 124-145). Treatment with LH induced pro-oestrus within 7 days (n = 16), and oestrus (n = 12) and fertile ovulations (n = 7) at 16 + 3 days, while pro-oestrus in bitches treated with saline did not occur until 46-166 days after the start of treatment. Six of the seven ovulating bitches whelped normal litters. The bitches in which pro-oestrus but not oestrus occurred were all treated in early anoestrus. During treatment, plasma oestradiol in bitches treated with LH increased from 8 + 2 pg ml-1 to 20 + 5 pg ml-1 within 1 day, and reached higher peak values (45 + 7 pg ml-1) (P < 0.05) than those observed in saline-treated controls (9 + 3 ng ml-1). These results demonstrate that LH treatment alone can terminate anoestrus by inducing a normal follicular phase in dogs. The results also suggest that, in normal cyclic bitches, anoestrus is the result of insufficient LH secretion, and that spontaneous pro-oestrus could be the result of increased LH secretion in the presence of already adequate concentrations of FSH.
authors.affiliation: Department of Small Animal Reproduction, University of Liege, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Verstegen
authors.forename: K
authors.initials: K
authors.lastname: Onclin
authors.forename: L
authors.initials: L
authors.lastname: Silva
authors.forename: P
authors.initials: P
authors.lastname: Concannon
mesh_terms: D000704:Analysis of Variance; D000780:Anestrus / Q000187:drug effects*; D000818:Animals; D004285:Dogs; D004958:Estradiol / Q000097:blood; D005260:Female; D005298:Fertility / Q000187:drug effects*; D008098:Litter Size; D007986:Luteinizing Hormone / Q000494:pharmacology*; D011374:Progesterone / Q000097:blood; D013552:Swine
chemical_list: D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone