title: Circadian variation of beta-endorphin-like immunoreactivity in neurointermediate pituitary.
abstract: Immunoreactive beta-endorphin-like activity (-IR) and ACTH-IR were determined in rat pituitary lobes and plasma at 4-hr intervals over a 24-hr period. In addition, we measured beta-endorphin-IR in discrete hypothalamic nuclei, and plasma corticosterone levels at the same time points. Significant and replicable circadian variation was detected only in concentrations of beta-endorphin-IR in neurointermediate pituitary and in plasma corticosterone concentrations.
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000276:immunology / Q000378:metabolism; D000818:Animals; D002940:Circadian Rhythm; D003345:Corticosterone / Q000097:blood; D004723:Endorphins / Q000276:immunology / Q000378:metabolism*; D008297:Male; D010902:Pituitary Gland / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D001615:beta-Endorphin
chemical_list: D004723:Endorphins; D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone; D003345:Corticosterone