Formation of formaldehyde from S-adenosyl-L-[methyl-3H]methionine during enzymic transmethylation of histamine

The experiments described here show that radiolabelled formaldemethone is formed from the radiolabelled methyl group of S-adenosyl-L-methionine in the course of the enzymic conversion of histamine to N tau-methylhistamine in the presence of dimedone suggesting that the formation of HCHO is probably linked to the enzymic transmethylation of histamine.