Abstract
Piperidine, possessing acetylcholine- and nicotine-like properties not only in the peripheral nervous system (1-3) but also in the central nervous system (4), has been described to be one of normal constituents in urine (5-7) and the mammalian brain (8-10). Recently, it has also been demonstrated in vitro that piperidine can be produced from pipecolic acid by decarboxylation in the presence of the brain tissue (11). It seems to be of great interest to study the distribution and physiological role of piperidine in living body. Therefore, it has been tried in our laboratory to develop a method applicable for the determination of micro amounts of piperidine in living materials. The present authors have already reported a quantitative determination method for piperidine by making use of color reaction due to the production of copper piperidino-dithiocarbamate (12) ; this method is sensitive but not specific for piperidine, and separation of the amine from other aliphatic amines is difficult. Recently, Asatoor (13, 14) has reported a method which is applicable for separation and detection of aliphatic and alicyclic amines in urine, however, this is available just for qualitative analysis.
The present paper deals with a new method which has been developed by further improvement of Asatoor's procedure in order to make the procedure fit the quantitative analysis of micro amounts of piperidine. Using this method, furthermore, the average amounts of piperidine in biological materials such as the pig brain and the urine of normal healthy students and schizophrenic patients, as a representative of psychoses, are also described.
