Involvement of endogenous opioid peptides in the antinociception induced by the novel dermorphin tetrapeptide analog amidino-TAPA.

The antinociceptive effect of i.t. administered N(alpha)-amidino-Tyr-d-Arg-Phe-beta-Ala (amidino-TAPA), an N-terminal tetrapeptide analog of dermorphin, was characterized in ddY mice.