The conversion of lysine into piperidine, cadaverine, and pipecolic acid in the brain and other organs of the mouse

Abstract
The biosynthesis of piperidine, a possible neuromodulator, and its presumed precursors cadaverine and pipecolic acid, has been investigated in the mouse under in vitro conditions. Conversion of lysine into piperidine was observed only in the intestines and is probably caused by the intestinal flora. Formation of cadaverine and pipecolic acid from lysine was observed in the brain, liver, kidney, and large intestine. In addition, pipecolic acid was formed in the heart. The possible contributions of the diet and of the intestinal bacteria to the endogenous pool(s) of piperidine are discussed.