Comparative observation of the pancreatic A and B cells by the enzyme antibody method: light microscopic findings in dog and mouse tissue.

A and B cells of pancreatic islets of the dog and mouse were stained by the enzyme-antibody method. A cells, in general, were small in number, particularly in the mouse, and distributed at the peripheral zone of the islet. Furthermore, A cells were located very close to the intrainsular capillary. On the other hand, B cells occupied dominantly the islet and mainly existed in its central area, especially in the mouse and not adjacent to the intrainsular capillary. A positively reacting cell with anti-insulin antibody was also found in the uncinate process of the dog pancreas, while there was no positively reacting cell with anti-glucagon antibody. This fact, as there were only two kinds of islet cells, B cell and the third cell of the islet (named D cell) in the uncinate process, showed that the D cell had neither glucagon nor glucagon-like immunoreactivity.