Des-tyrosine1-gamma-endorphin increases the antinociceptive efficacy of morphine in the rat.
Repeated injections of des-tyrosine1-gamma-endorphin (DT gamma E) to rats subjectively increased sensitivity to handling. After 8 days of treatment, the animals were supersensitive to a low dose of morphine in the foot-shock test. Acute treatment with DT gamma E gave no significant increase in morphine sensitivity. The results indicate that DTgammaE given chronically interacts with opioid receptor-effector mechanisms.
D000698:Analgesia; D000818:Animals; D004351:Drug Resistance; D004357:Drug Synergism; D004723:Endorphins / Q000494:pharmacology*; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D010446:Peptide Fragments / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
D004723:Endorphins; D010446:Peptide Fragments; C018903:gamma-endorphin, des-Tyr(1)-; D009020:Morphine