Impromidine was found to have a positive inotropic effect on the isolated papillary muscle from the guinea-pig. The dose-response curve to impromidine was shifted to the right by cimetidine and ranitidine. Impromidine was 35 times more potent than histamine but with a maximal response of only 81% that obtained with histamine. This difference, which was statistically significant (P < 0.005), suggested that impromidine acts as a partial agonist at the histamine H2-receptors of the papillary muscle as has been observed in other tissues.
No takes yet. Share an insight, caveat, or question.
Bertaccini et al. (1981) studied this question.
Synapse has enriched one closely related paper. Consider it for comparative context: