The analgesically effective peptide deprolorphin exhibits cross-tolerance to morphine in rats.
The potent analgesically active beta-casomorphin derivative, D-Pro4-beta-casomorphin 1-5 (= Deprolorphin), was tested for its capacity to induce tolerance. In animals tolerant to morphine, a previously analgesically effective test dose of the peptide was without any antinocipetive effect, demonstrating a cross-tolerance between morphine and deprolorphin.
D000700:Analgesics; D000818:Animals; D004361:Drug Tolerance; D004567:Electrodes, Implanted; D004723:Endorphins / Q000494:pharmacology*; D008297:Male; D009020:Morphine / Q000494:pharmacology*; D010446:Peptide Fragments; D051381:Rats; D011919:Rats, Inbred Strains
D000700:Analgesics; D004723:Endorphins; D010446:Peptide Fragments; C034812:beta-casomorphin 5; D009020:Morphine