Eseroline: a new antinociceptive agent derived from physostigmine with opiate receptor agonist properties. Experimental in vivo and in vitro studies on cats and rodents

We report that eseroline, until now thought devoid of any biological action, is a potent antinociceptive agent. Its antinociceptive action is stronger than that of morphine in all tests studied and, though shorter lasting than that of the latter, has a latency of only a few minutes by subcutaneous route. Eseroline, like morphine and enkephalins, inhibits the electrically evoked twitches of the mouse vas deferens and of the guinea-pig ileum. Eseroline, moreover, releases 5-hydroxytryptamine from cat brain cortex in way similar to that of morphine and physostigmine.