title: Buserelin alters the development of the corpora lutea in cyclic and early postpartum cows.
abstract: Changes in proportions of luteal cells after buserelin treatment were studied in the corpus luteum (CL) that was present at the time of treatment (CLP) and in the buserelin-induced CL (CLI) of cyclic and acyclic postpartum cows. On d 0 of the experimental period, eight cyclic (Cyc-sal) cows were injected with saline, whereas eight cyclic (Cyc-bus) cows and eight acyclic (Acyc-bus) cows were treated i.m. with 8 micrograms of buserelin. On d 3 or 6, ovaries were collected and stained using histological techniques. As determined with the point-counting method, the number of nuclei in the CLP was similar on d 3 in Cyc-bus and Cyc-sal groups but was lower (treatment x day, P < .001) in the Cyc-bus group than in the Cyc-sal group on d 6. The volume of the CLP was similar on d 3 in the two groups but was greater (treatment x day, P < .04) in the Cyc-bus than in the Cyc-sal group on d 6. The number of nuclei in the CLI was greater (P < .001) in cyclic than in acyclic cows on d 3 and 6 after treatment. The volume of the CLI was lower (P < .001) in cyclic than in acyclic cows on d 3 and 6. Buserelin did not change the profile of progesterone in cyclic cows from d 0 to 6, but concentrations of progesterone increased (P < .01) in acyclic cows 3 to 6 d after buserelin treatment.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Département des Sciences Animales, Université Laval, Québec, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Twagiramungu
authors.forename: L A
authors.initials: LA
authors.lastname: Guilbault
authors.forename: J G
authors.initials: JG
authors.lastname: Proulx
authors.forename: J J
authors.initials: JJ
authors.lastname: Dufour
mesh_terms: D000818:Animals; D002064:Buserelin / Q000494:pharmacology*; D002417:Cattle / Q000378:metabolism / Q000502:physiology*; D003338:Corpus Luteum / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D003433:Crosses, Genetic; D004971:Estrus / Q000502:physiology*; D005260:Female; D049590:Postpartum Period / Q000502:physiology*; D011374:Progesterone / Q000097:blood; D011897:Random Allocation; D013997:Time Factors
chemical_list: D011374:Progesterone; D002064:Buserelin