title: Dynorphin (1-13): analgesia, hypothermia, cross-tolerance with morphine and beta-endorphin.
abstract: Intracerebroventricular administration of 20, 40 and 60 nmol of dynorphin (1-13) produced analgesia, as assessed by flinch/jump response to footshock, and hypothermia in the rat. Rats developed tolerance to both the analgesic and thermic effects of the 20 nmol dose of dynorphin. Dynorphin and beta-endorphin showed cross-tolerance with respect to their analgesic but not their thermic effects. Dynorphin and morphine also produced cross-tolerant analgesic effects. Naloxone (10 mg/kg, IP) completely blocked the barrel rolling produced by 20 nmol dynorphin but did not alter its analgesic or thermic effects.
mesh_terms: D000698:Analgesia; D000700:Analgesics; D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D004347:Drug Interactions; D004361:Drug Tolerance; D004399:Dynorphins; D004723:Endorphins / Q000494:pharmacology*; D007700:Kinetics; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D009270:Naloxone / Q000494:pharmacology; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D001615:beta-Endorphin
chemical_list: D000700:Analgesics; D004723:Endorphins; D010446:Peptide Fragments; D009270:Naloxone; D001615:beta-Endorphin; C026843:dynorphin (1-13); D004399:Dynorphins; D009020:Morphine