Abstract
The incorporation of choline into phosphatidylcholine in mammary tissue from lactating cows is impeded by 2-chloroethyltrimethylammonium chloride at concentrations ranging from 0.3 to 9mm. This compound is a non-competitive inhibitor of choline kinase (Km 0.25mm), having Ki 17mm. It is suggested that 2-chloroethyltrimethylammonium chloride may inhibit choline entry into the tissue.