Structure and Metabolism of the Pancreatic Islets in Streptozotocin Treated Guinea Pigs

Guinea pigs injected with streptozotocin showed temporary hyperglycemia and retardation of body growth. One month after streptozotocin injection the islets of Langerhans of these animals consisted mainly of A 2 -cells. Compared to the control animals the nuclei of the B- and A 1 -cells were increased in size. Microrespirometric analyses of the isolated islets from streptozotocin-treated animals showed that the endogenous respiratory rate was in the same range as that of islets from the controls. Addition of D-glucose to the incubation medium caused a stronger stimulation of the oxygen uptake in the control islets than in the islets from the streptozotocin-treated animals. However, when the medium was supplemented with succinate the islets from the latter animals had a higher oxygen uptake. The predominance of A 2 -cells in these islets supports the idea that the results are representative mainly for this cell type. The results may thus reflect a fundamental difference in the metabolism between the Band A 2 -cells.