EPIDERMAL GROWTH-FACTOR BINDING-SITES IN THE MOUSE EXOCRINE AND ENDOCRINE PANCREAS SHOWN BY IN-VIVO QUANTITATIVE MICROAUTORADIOGRAPHY AND CONFOCAL LASER-SCANNING MICROSCOPY

Microautoradiography at 3, 6 and 15 min after intravenous injection of I-125-EGF was used to investigate the distribution of epidermal growt h factor (EGF) binding sites in the pancreas of normal male mice. The autoradiographs were observed by confocal laser microscopy, which allo ws the quantification of silver grains. The results demonstrated that both endocrine and exocrine pancreatic cells exhibited substantial spe cific binding of I-125-EGF. The highest level of EGF binding was found in the duct cells of the exocrine pancreas followed by the acinar cel ls. The cells of the islets of Langerhans also showed substantial spec ific binding of I-125-EGF though the binding level was lower than that of the exocrine pancreas. In the control experiments, mice were injec ted with I-125-EGF and various amounts of unlabeled EGF.