CARDIOVASCULAR ACTIONS OF THREE CHOLINE ESTERS OF CARBOXYALKYLIMIDAZOLE

¹ Department of Pharmacology, Research Division, Schering Corporation, Bloomfield, New Jersey

The cardiovascular actions of imidazolepropionylcholine (ImPrCh), imidazoleacrylcholine (ImAcrCh) and imidazoleacetylcholine (ImACh) were studied in anesthetized dogs. Intraarterial injection (femoral) of these choline esters produced local vasodilatation similar to that of acetylcholine (ACh) and histamine. Intravenous injection produced a transient period of hypotension followed by a more prolonged period of hypertension similar to that of 1,1-dimethyl-4-phenylpiperazinium (DMPP).

The vasodilatation resulting from intraarterial injection of ImPrCh, ImAcrCh, ImACh or ACh was blocked by intravenous injection of atropine but not by hexamethonium. The hypertension produced by intravenous injection of ImPrCh, ImAcrCh, ImACh or DMPP was blocked by hexamethonium. DMPP, by the intraarterial route, produced local vasodilatation blocked by hexamethonium. The results were interpreted as indicating that ImPrCh, ImAcrCh and ImACh can stimulate both at the autonomic ganglia and at the peripheral cholinergic neuro-effector sites.

The hypotensive action of intravenous histamine or the vasodilator action of1 intraarterial histamine was not potentiated by the ImPrCh or aminoguanidine.