Morphine and beta-endorphin antagonize posture and locomotor disorders induced by the injection of ACTH 1-24 in the rat locus coeruleus.
The unilateral microinjection of ACTH 1-24 (20 nmol) into the locus coeruleus (LC) produced a long lasting (2-3 hr) posture asymmetry and movement disorder in all rats tested. This response was readily suppressed by the subsequent local microinjection of an equimolar dose of beta-endorphin or morphine or by the intraperitoneal injection of morphine sulphate (50 mg/kg). Microinjection of naloxone (20 nmol) into the LC produced the above syndrome in a lower percentage of animals. The results support the hypothesis that ACTH peptides and opioids play opposite roles in the control of different brain functions.
D000324:Adrenocorticotropic Hormone / Q000031:analogs & derivatives*; D000818:Animals; D003366:Cosyntropin / Q000008:administration & dosage / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D004409:Dyskinesia, Drug-Induced; D004723:Endorphins / Q000008:administration & dosage / Q000494:pharmacology*; D008125:Locus Coeruleus / Q000187:drug effects*; D008297:Male; D008845:Microinjections; D009020:Morphine / Q000008:administration & dosage / Q000494:pharmacology*; D009270:Naloxone / Q000008:administration & dosage / Q000494:pharmacology; D011187:Posture; D051381:Rats; D011919:Rats, Inbred Strains; D001615:beta-Endorphin
D004723:Endorphins; D003366:Cosyntropin; D009270:Naloxone; D001615:beta-Endorphin; D009020:Morphine; D000324:Adrenocorticotropic Hormone