Ultrastructural localization of adenyl cyclase activity in the pancreas of two amphibian species (Salamandra salamandra L. and Rana esculenta L.).

The distribution of adenyl cyclase activity in the pancreas of one species of urodeles and anura has been investigated using electron microscopy. In both islet and acinar tissues the reaction product was located at the outer cell surfaces, while in nerve bundles it occurred in the cleft between axolemma and Schwann cell-extensions. The functional signification of the enzyme localization is discussed in relation to the findings of other authors.