[The metabolism of fluorogenic monoamines during the differentiation of embryonic pancreatic endocrine cells of birds].

The FIF technique applied to embryonic pancreas of the chick shows that the islte cells of the splenic lobe are able to take up L-DOPA and to synthesize high amounts of catecholamines from the 4th day of incubation. In the ventral pancreatic lobes fluorescent cells are not detectable before day 12. Later on, islet cells of the whole organ spontaneously accumulate fluorogenic amines and L-DOPA injection greatly increases the intensity of the fluorescence. It appears that in endocrine pancreas, as in various other polypeptide hormone producing cells, an aminoacid decarboxylase activity is detectable early in the differentiating process and precedes the amine storage. The possible role of fluorogenic monoamines in functional differentiation is discussed.