Differential effects of D-Ala2 analogues of enkephalins on substance P-induced analgesia in rodents.
The systemic administration of subanalgesic doses of [D-Ala2, D-Leu5]enkephalin significantly potentiated the analgesia elicited in rats or mice by intraventricular injection of substance P. On the contrary, systemic administration of low doses of [D-Ala2,Met5]enkephalinamide antagonized the substance P-induced analgesia. The results support the notion of different physiological functions for the enkephalins and suggest an integrated role for enkephalins and substance P in the control of pain at supraspinal levels.
D000818:Animals; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D016308:Enkephalin, Leucine-2-Alanine; D004744:Enkephalin, Methionine / Q000031:analogs & derivatives* / Q000494:pharmacology; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains; D013373:Substance P / Q000494:pharmacology*
D013373:Substance P; D004744:Enkephalin, Methionine; D004743:Enkephalin, Leucine; C013801:enkephalin-Met, Ala(2)-; D016308:Enkephalin, Leucine-2-Alanine