Activity of analogues of decamethonium on the chick biventer cervicis preparation.

The abilities of various decamethylenebisammonium compounds to cause contracture of the chick biventer cervicis preparation have been compared quantitatively with that of decamethonium. In the compounds tested the 1,10 substituents were similar and were ethyldimethylammonium, diethylmethylammonium, triethylammonium, hydroxyethyldimethylammonium and acetoxyethyldimethylammonium; decamethylenebisdimethylamine was also tested. The activity of the bisethyldimethylammonium compound is about one-third of that of decamethonium, that of the bisdiethylmethylammonium compound about one-twenty-eighth, but the other compounds are much less than one-hundredth as active. Even the bistriethylammonium compound, however, has some detectable activity although it is only a partial agonist. It is suggested that ability to depolarize the preparation depends upon the presence of methyl groups attached to the quaternary ammonium atom and also upon the presence of two such onium groups at the ends of the decamethylene chain. In these compounds the acetoxy group reduces ability to depolarize the preparation.