Synthesis and storage of epithelial-epidermal growth factor in submaxillary gland.

Abstract

Summary Epithelial-epidermal growth factor (EGF) is a purified protein derived from mouse submaxillary gland that appears to function as a hormone to induce the growth of epidermis and of normal and neoplastic mammary cells. Immunofluorescent staining demonstrated the presence of this factor in specific tubular cells of the submaxillary gland, although it was not detected in any other mouse tissues. EGF was also detected in the rat and rabbit by its immunological cross-reactivity with the mouse antigen and by its biological activity on mouse mammary gland. However, it was not detectable by these criteria in the submaxillary glands of several other species including the human. Organ cultures of mouse submaxillary gland incorporated 14 C-labeled amino acids into protein that was shown to be identical to authentic EGF by polyacrylamide gel electrophoresis after purification by specific immunoabsorption. This result indicates that EGF is synthesized by mouse submaxillary cells and thus suggests that elaboration of EGF may be a specific function of these cells.