Neurochemical and structural studies of the mechanism of action of hemicholinium 3 in central cholinergic synapses

G. RODRÍGUEZ DE LORES ARNAIZ; L. M. ZIEHER; E. DE ROBERTIS

JOURNAL OF NEUROCHEMISTRY

WILEY-BLACKWELL PUBLISHING, INC

Año: 1970 vol. 17 p. 221 - 229

0022-3042

Abstract-The action of hemicholinium-3 (HC-3) on the cerebral cortex of the rat was studied after subarachnoidal administration. There was a marked decrease of content of ACh in nerve endings and especially in the fraction containing synaptic vesicles, despite the fact that the number of synaptic vesicles was not reduced, as judged by electron microscopy,by the rate of incorporation of ortho [32P]phosphate, and by the phosphorus content of the phospholipids of the isolated synaptic vesicles. There was a close association of [14C]HC-3 and of monoaminoxidase, which indicated that the drug was preferentially bound to mitochondria. Experiments indicating that HC-3 could be acetylated suggested that this drug may compete with choline not only for entry but also for acetylation.