Circadian periodicities of serum androgens, progesterone, gonadotropins and luteinizing hormone-releasing hormone in male rats: the effects of hypothalamic deafferentation, castration and adrenalectomy.
Serum testosterone (T), dihydrotestosterone (DHT), progesterone (P), LH, FSH and luteinizing hormone-releasing hormone (LHRH) levels and the LHRH content in the medial basal hypothalamus (MBH) and preoptic area (POA) were estimated during a 24-h period. Circadian rhythms, temporally unrelated to each other, were evident in serum FSH and LHRH and the MBH LHRH content; serum LH fluctuated randomly. In addition, serum T and DHT demonstrated a parallel circadian pattern while serum T and P appeared inversely related. Serum P rhythm persisted in long-term castrate males. Without adversely affecting serum LH, anterior hypothalamic deafferentation abolished both serum T and P rhythms, whereas adrenalectomy obliterated only the serum T periodicity. These studies show that the POA-MBH complex and the adrenals play important roles in the circadian regulation of testicular secretions.
D000315:Adrenalectomy; D000344:Afferent Pathways; D000818:Animals; D002369:Castration; D002940:Circadian Rhythm; D013196:Dihydrotestosterone / Q000097:blood*; D005640:Follicle Stimulating Hormone / Q000097:blood*; D007987:Gonadotropin-Releasing Hormone / Q000097:blood*; D007031:Hypothalamus / Q000502:physiology*; D007700:Kinetics; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D011374:Progesterone / Q000097:blood*; D051381:Rats; D012737:Sex Factors; D013739:Testosterone / Q000097:blood*
D013196:Dihydrotestosterone; D007987:Gonadotropin-Releasing Hormone; D013739:Testosterone; D011374:Progesterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone