title: [Circadian rhythm of cortisol levels and its precursors in different phases of the menstrual cycle in baboons].
abstract: Radioimmunoassays were used to study in experiments on sacred baboons the circadian rhythms of dehydrocortisone, 11-deoxycortisol, progesterone, pregnenolone and 17-hydroxypregnenolone in the folliculin and luteal phases of the menstrual cycle. The circadian rhythms of dehydrocortisone and 11-deoxycortisol secretion were seen in both phases of the cycle. The maximum content of the plasma steroids were recorded in the morning while the minimum one in the evening and at night. The circadian rhythm of the progesterone level in the folliculin phase correlated with the time course of changes in dehydrocortisone concentration. In the luteal phase, the maximum hormonal levels were seen in the evening and at night. The circadian rhythms of pregnenolone and 17-hydroxypregnenolone secretion were not pronounced in the folliculin phase. However, in the second half of the cycle, the amplitude of circadian rhythms increased, correlating with the dehydrocortisone level rhythm. The daily average concentration of the adrenal steroids tended to decrease in the luteal phase of the baboon menstrual cycle.
mesh_terms: D000818:Animals; D002940:Circadian Rhythm; D005260:Female; D005498:Follicular Phase; D006854:Hydrocortisone / Q000097:blood*; D008183:Luteal Phase; D008598:Menstruation; D010215:Papio; D011282:Pregnenediones / Q000097:blood*
chemical_list: D011282:Pregnenediones; D006854:Hydrocortisone
vernacular_title: Tsirkadnyĭ ritm urovnia kortizola i ego predshestvennikov v razlichnye fazy menstrual'nogo tsikla u pavianov gamadrilov.