DISTRIBUTION OF LABELLED STREPTOZOTOCIN IN MICE: UPTAKE AND RETENTION IN PANCREATIC ISLETS

Abstract

The distribution of labeled streptozotocin in mice was studied by whole body and microautoradiography, and an uptake was found in the islets. At least in mice, uptake and retention of streptozotocin in the pancreatic islets are apparently important factors in its toxic effect towards that tissue. It was not possible to determine which type(s) of islet cells were labeled, but the observation that the peripherally located cells often showed a lower labeling than the other islet cells may indicate a selective labeling of .beta.-cells. Uptake was seen at the shortest survival interval, which may indicate that the unchanged streptozotocin molecule is taken up by the islet tissue. The observation that the radioactivity was retained in the pancreatic islets at a higher level than in other organs suggests a specific binding of streptozotocin (or part of its molecule) or possibly a low degrading activity for streptozotocin (or some breakdown product(s)) in the pancreatic islets.