Analgesic effects of enkephalin analogs in rats.
The analgesic effects of intracerebroventricular injections of Met-enkephalin and five of its analogs in a dose of 10 micrograms each were quantified with a hot plate test in rats. Two analogs showed analgesic effect. [D-Ala2, Met5]-enkephalin had a weak and short-lasting analgesic effect. [D-Ala2, Met5]-enkephalinamide (DALA) had a striking and long-lasting analgesic effect. However, sulfation of tyrosine residue totally abolished the analgesic action of DALA. The analgesic effect of DALA was not affected by preinjection of its sulfated analog.
D000698:Analgesia; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives / Q000494:pharmacology; D004745:Enkephalins / Q000494:pharmacology*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors
D004745:Enkephalins; C042667:enkephalinamide-Leu, Tyr sulfate(1)-; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; C021055:Met-enkephalinamide; C022118:enkephalinamide-Met, Ala(2)-; C013801:enkephalin-Met, Ala(2)-; C042668:enkephalinamide-Met, Tyr sulfate(1)-Ala(2)-