[Electron microscopic-cytochemical study of the effect of vinblastine on synaptosome adenylate cyclase in the rat...

Adenylate cyclase activity was demonstrated by means of electron microscopic cytochemistry in rat cortical synaptosomes incubated under various conditions. It was found that vinblastine caused remarkable changes in the reaction product localization: the limiting membrane reaction diminished, but the number of synaptosomes were seen to contain a course granular precipitate filling up almost the whole presynaptic cytoplasm. The regulatory role the microtubules play in the distribution of adenylate cyclase on cellular membrane is discussed.