The subcellular distribution of substance P in the nervous tissues.

HEBB and WHITTAKER (1958) have described the isolation of a subcellular fraction of brain tissue which contains the bound acetylcholine (ACh) and choline acetylase. This fraction was further studied by WHITTAKER (1959), his results providing an evidence for physiological significance of his "synaptic vesicle fraction". On the other hand, it has been reported hitherto, that substance P (SP) is present abundantly in some regions of central nervous system (KOPERA and LAZARINI, 1953; PERNOW, 1953; AMIN et at., 1954; TSUJIOKA, 1958). A probable physiological role of SP in the central nervous system has been also discussed by some investigators (UMRATH, 1953 and 1956; LEMBECK, 1953; PATON, 1958; CROSSLAND, 1960). And so the present author attempted to apply WHITTAKER'S fractionation method to study subcellular distribution of SP and of a specific enzyme capable of destroying its activity. It was confirmed that SP is found chiefly in the synaptic vesicle and supernatant fractions, while SPinactivating enzyme mainly in the latter one. This report is mainly concerned with such a subcellular distribution of SP in the central nervous system. A brief communication on some of the experimental results included in this paper has been presented at the general meeting of the Japanese Physiological Society at Kyoto (April, 1961).