Reduced behavioral effectiveness of ACTH(1-24) after a second administration: interaction with opiates.
Repeated intraventricular administration of ACHT results in reduction of subsequent ACTH-induced grooming behavior. A previous injection of beta-endorphin, (D-Phe(7))ACTH(4-10), or morphine, also reduces the behavioral response to a subsequent injection of ACTH. The reduction in grooming as a result of repeated administration is not mediated by corticosteroid feedback and can be eliminated by pretreatment with the opiate antagonist naloxone.
Jolles
J
J
Division of Molecular Neurobiology, Rudolf Magnus Institute for Pharmacology, State University of Utrecht, Padualaan 8, Utrecht, The Netherlands.
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