K.: The ganglionic blocking action of Dibutolin

In 1943 Swan and White (1) studied a series of choline esters with atropine-like properties. The dibutyl urethane of choline, and a closely related compound, the dibutyl urethane of dimethylethyl-$-hydroxyethyl ammonium sulfate, were selected for clinical trial as mydriatic and cycloplegic agents. In a pharmacologi-cal study of the actions of the latter compound (“Dibutoline”), Peterson and Peterson (2) demonstrated blockade of the actions of acetyicholine and para-sympathetic nerve stimulation on cholinergic effector organs, but stated that the drug possessed no “nicotinic paralyzing ” action. Some of the characteristics of the cardiovascular responses to Dibutoline, however, suggested that blockade of autonomic ganglia was produced by the drug. In dogs anesthetized with pento-barbital Dibutoline caused a decrease of heart rate not affected by atropine or by vagotomy, and a fall of blood pressure limited in extent. Both are characteristic features of the cardiovascular actions of tetraethylammonium salts (3). The following experiments were planned to determine whether Dibutoline possesses ganglionic blocking activity in addition to its atropine-like action