Cytochemical localization of Ca2+-ATPase activity in the guinea pig sympathetic ganglia.

Cytochemical techniques were used to study the localization of a calcium-dependent ATPase in sympathetic ganglia of the guinea pig. Enzymatic activity was revealed on the external surface of the plasma membranes of both neurons and satellite cells. The neurons displayed enzymatic activity in the membranes of non-specialized neuronal boundaries as well as at synaptic specializations. In some terminals the synaptic vesicles contained enzymatic reaction products. The findings are interpreted to indicate that these sites are involved in the regulation of calcium ion concentration and in cellular processes in which calcium ions are key messengers.