Autoradiographic studies on the distribution of quaternary ammonium compounds. II. Distribution of 14 C-labeld decamethonium, hexamethonium and dimethonium in mice.

The distributions of 14C-labeled decamethonium, hexamethonium and dimethonium in mice after intraperitoneal injection were compared by whole-body autoradiographic technique and the results discussed in relation to the progressive change in the structure and to the pharmacological effect. The rate and the extent of accumulation in the liver was increased in the order of di- hexa->decamethonium. As a common feature for the bisquaternary ammonium, the all compounds showed a rapid accumulation and a long retention in the cartilage and hexa-and decamethonium in the meninges, possibly in the arachnoid. No penetration was detected in the brain parenchyma. The all bisquaternary structure did not show any accumulation in the salivary gland and other secretory glands, where monoquaternary structure appears to be accumulated. Only decamethonium, a muscle relaxant, showed a high accumulation in the muscular tissues, while hexamethonium, a ganglionic depressant, as well as dimethonium which is inert pharmacologically did not show any accumulation. These results and a finding that tetraethylammonium, another ganglionic depressant, did not show any accumulation might indicate a presence of a direct relation between the distribution of a drug in macro level and the appearence of the pharmacological action.