title: [Annual variations in plasma prolactin and testosterone concentrations in the Ouled-Djellal ram in Algeria].
abstract: Plasma concentrations of prolactin and testosterone were measured weekly, from November 1976 to December 1977, respectively in 29 and 10 Ouled-Djellal rams penned in the Algeria area. Plasma prolactin and testosterone levels exhibited concomitant seasonal variations: they were low in November-December, then they increased from January to maximal values in summer through two steps, the first in February-March, the second in June-July. Taken all around, the hormones changes paralleled those of photoperiod. The synchronism in annual variations of prolactin and testosterone secretory patterns is a feature of the Ouled-Djellal ram. Results are discussed in relation to effects of prolactin on testicular activity.
mesh_terms: D000462:Algeria; D000818:Animals; D002980:Climate; D008297:Male; D010507:Periodicity; D011388:Prolactin / Q000097:blood*; D012621:Seasons; D012756:Sheep / Q000502:physiology*; D013696:Temperature; D013739:Testosterone / Q000097:blood*
chemical_list: D013739:Testosterone; D011388:Prolactin
vernacular_title: Variations annuelles des concentrations plasmatiques en prolactine et en testostérone chez le Bélier Ouled-Djellal, en Algérie.