Protective effect of 4,6-O-ethylidene glucose against the cytotoxicity of streptozotocin in pancreatic beta cells in vivo: indirect evidence for the presence of a glucose transporter in beta cells.

Ethylidene glucose (4,6-O-ethylidene glucose; EG) is known to bind the outer surface of the glucose transporter in the membranes of human erythrocytes and other mammalian cells. If a glucose transport system is present on pancreatic beta cells and recognizes the glucose moiety of streptozotocin (STZ), EG should protect beta cells from the cytotoxicity of STZ when it is administered with STZ. This possibility was examined in in-vivo experiments in rats. When EG and STZ were injected into rats together the animals did not become diabetic, as judged by their blood glucose levels, response in a glucose-tolerance test, and insulin secretion in response to feeding. These results suggest that there is a glucose transporter present in beta cells and also the transport of streptozotocin into beta cells through this system.