The suprachiasmatic nuclei stimulate evening ACTH secretion in the rat.
The effect of bilateral lesions of the suprachiasmatic nuclei (SCN) on the circadian rhythm in ACTH was studied in rats that were adrenalectomized and implanted with a subcutaneous corticosterone (B) pellet. Rats wee chronically cannulated to allow for repeated blood sampling. In rats with B pellets, bilateral lesions of the SCN eliminated the circadian rise in plasma ACTH seen in sham-lesioned animals. This is consistent with the idea that the SCN stimulate ACTH secretion in the evening.
Cascio
C S
CS
Department of Physiology, University of California School of Medicine, San Francisco 94143.
Shinsako
J
J
Dallman
M F
MF
D000315:Adrenalectomy; D000324:Adrenocorticotropic Hormone / Q000097:blood / Q000378:metabolism*; D000818:Animals; D002940:Circadian Rhythm; D003345:Corticosterone / Q000097:blood / Q000494:pharmacology; D004343:Drug Implants; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013493:Suprachiasmatic Nucleus / Q000502:physiology*
D004343:Drug Implants; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone