Effects of N-Ethoxycarbonyl-3-Mqrpholinosydno-Nimine (Sin-10) on the Cardiovascular System

Sydnonimine derivatives, a series of mesoionic compounds, have a peculiar feature in their molecular structure and biological activities. The smooth muscle relaxing action of the compounds has been reported on the rat duodenum and the guinea-pig ileum by Oehme et al. (1) and hypotensive effect by Daeniker and Druey (2). Recently, 3-substituted sydnonimines were newly synthetized (3) and were found to have potent vasodepressor activities (4, 5). Of these compounds, a derivative, whose imino radical at 5 position was acylated with ethoxycarbonyl group to make N-ethoxycarbonyl-3-morpholinosydnonimine (SIN-10), became more stable and was reported to produce a potent and persistent hypotension in anesthetized dogs and rabbits (4, 5). The present study deals with the effects of SIN-10 on cardiovascular system and the analysis of mechanism of action involved in hypotensive effect of the drug in anesthetized dogs and cats.