Cytochemical localization of 5'-nucleotidase in the enteric ganglia and in smooth muscle cells of the guinea-pig.

Cytochemical techniques were used to study the localization of 5'-nucleotidase in the enteric ganglia and in smooth muscle cells of the guinea-pig ileum, iris and vas deferens. Enzymatic activity was revealed in plasma membranes and caveolae of smooth muscle cells and in neurons and neuroglia of the enteric ganglia. The strongest activity was seen in the membrane of the smooth muscle cells, especially the caveolae intracellulares, and this was interpreted to indicate a high level of purine utilization and involvement in calcium translocation by these cells. The ganglia displayed enzymatic activity in the membranes of non-specialized neuron-to-glia boundaries as well as at some synaptic specializations. This finding is consistent with a possible release of adenine nucleotides within the ganglia.