Antinociceptive properties of a new tetrapeptide, Asn-Ala-Gly-Ala, in mice.
The effect of intracerebroventricularly (i.c.v.) administered Asn-Ala-Gly-Ala (NAGA), a partial sequence of beta-lipotropin, was investigated using the tail-pressure, hot-plate and phenylbenzoquinone (PBQ)-induced writhing tests in mice. I.c.v. administration of NAGA produced a dose-dependent inhibition of responses as measured by the three different assays. The ED50 of NAGA on the tail-pressure test did not differ from that obtained on the hot-plate test. NAGA showed a prominent reduction in activity on the PBQ writhing as compared with the hot-plate and tail-pressure tests. A low dose of naloxone (0.1-1.0 mg/kg, s.c.) resulted in a dose-dependent antagonism of the effect of NAGA in all assays. These data suggest that the antinociceptive effect induced by NAGA may involve the endogenous opioid system in mice.
D000700:Analgesics / Q000494:pharmacology*; D000818:Animals; D016227:Benzoquinones; D004744:Enkephalin, Methionine / Q000494:pharmacology; D007276:Injections, Intraventricular; D008297:Male; D051379:Mice; D009270:Naloxone / Q000494:pharmacology; D009842:Oligopeptides / Q000494:pharmacology*; D011809:Quinones / Q000494:pharmacology; D011930:Reaction Time / Q000187:drug effects; D013997:Time Factors
D000700:Analgesics; D016227:Benzoquinones; D009842:Oligopeptides; D011809:Quinones; C029322:phenylbenzoquinone; D009270:Naloxone; D004744:Enkephalin, Methionine; C038175:asparaginyl-alanyl-glycyl-alanine