Cytochemical localization of adenylate cyclase in broken cell preparations of the cerebral cortex

Broken cell preparations derived from rat cerebral cortical grey matter were studied cytochemically to localize adenylate cyclase (AC) activity in subcellular organelle membranes. AC activity was localized by visualizing reaction product in brain particulate fractions by electron microscopy. Activity was found in the endoplasmic reticulum, on the inside of the inner mitochondrial membrane and on both leaflets of the nuclear membrane. Reaction product was found in the postsynaptic density area of most synapses. The reaction product tended to be more prominent in the presence of fluoride. A synaptosome-rich fraction was shown to have NE stimulated AC activity which was blocked in vitro by both a alpha- and an beta-blocker and in vivo by propranolol.