[Presence of an insulinlike protein in the submandibular salivary glands of man and agricultural animals].

An insulinlike protein (ILP) has been extracted from the submaxillary glands of men, bulls and boars. Its electrophoretic mobility is similar to that of the cristalline insulin. In addition, electrophoregrams of bulls and boars show that levels of the main zones of ILP and the insulin extracted from the pancreas by the same method coinside. Immunological properties of ILP and those of insulin are identical. The immuno-fluorescence method has detected ILP in striated ducts of the salivary glands. Nonspecific luminescence in these ducts is revealed around the human gland nuclei and is likely to be caused by the presence of lysosomes. It is not yet clear what microstructures are responsible for LIP localization in salivary ducts.