[Effect of met- and leu-enkephalins and their synthetic analog on stimulation and acupunture analgesia].

Experiments on unrestrained rats were carried out to study the effect of intraventricularly injected met- and leu-enkephalins and their synthetic analog Tyr-dAla-Cly-Phe-NH2 on analgesia induced by electrical stimulation of the central gray. It was shown that subanalgesic doses of enkephalins and their synthetic analog facilitated the appearance of analgesic action on subthreshold antinociceptive-brain stimulation and potentiated the analgesic effect of threshold central gray stimulation. Subanalgesic and low analgesic doses of the peptides increased antinociceptive effect of electroacupuncture. The data obtained are discussed from the standpoint of the implication of the peptidergic mechanisms in the realization of acupuncture and stimulation analgesia.