Quantitative Electron Microscopic Autoradiography of Insulin, Glucagon, and Somatostatin Binding Sites on Islets

Abstract
After monolayer cultures of rat islets were exposed to [125I]insulin,[125I]glucagon, and [125I]tyrosinyl somatostatin, specific autoradiographic grains associated with each radioactively labeled ligand were found on B, A, and D cells.The density of labeling of the B, A, and D cells with each labeled ligand correlated well with the known actions of the three hormones on each of the islet cells.