title: Effect of prolonged treatment with tetracosactrin on hypothalamo-pituitary-adrenal function in the rat.
abstract: 1. The functional integrity of the hypothalamo-pituitary adrenal (HPA) system was assessed in rats after prolonged treatment with tetracosactrin.2. Adrenal size and sensitivity to corticotrophin were increased.3. Both the circadian rhythm and the stress-induced increase in HPA activity were inhibited. The circadian rhythm recovered before the response to stress.4. Tetracosactrin given after betamethasone treatment delayed the return of a normal HPA response to stress.5. Suppression of HPA activity appeared to be the result of a direct action of tetracosactrin and not entirely due to the elevations in the plasma corticosterone concentration which it caused.
mesh_terms: D000311:Adrenal Glands / Q000033:anatomy & histology / Q000187:drug effects* / Q000502:physiology; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D001623:Betamethasone / Q000494:pharmacology; D002940:Circadian Rhythm / Q000187:drug effects; D003345:Corticosterone / Q000097:blood; D004357:Drug Synergism; D007031:Hypothalamus / Q000187:drug effects* / Q000502:physiology; D008297:Male; D009929:Organ Size; D010455:Peptides / Q000494:pharmacology; D010902:Pituitary Gland / Q000187:drug effects* / Q000502:physiology; D051381:Rats; D013312:Stress, Physiological / Q000503:physiopathology
chemical_list: D010455:Peptides; D000324:Adrenocorticotropic Hormone; D001623:Betamethasone; D003345:Corticosterone