TREATMENT OF CULTURED PANCREATIC B-CELLS WITH STREPTOZOTOCIN INDUCES CELL-DEATH BY APOPTOSIS

Treatment of cultured pancreatic B-cells (HIT-T15 and RINm5F) with the diabetogenic drug streptozotocin resulted in a significant increase i n the number of cells that became detached from the substrate during a subsequent culture period. Examination of the detached cells by fluor escence microscopy after staining with acridine orange or by electron microscopy revealed evidence of chromatin condensation and margination . Isolation and fractionation of DNA from these cells revealed a patte rn of oligonucleosomal fragmentation that was not evident in untreated cells. All of these features are characteristic of entry of the cells into apoptosis and the results suggest that the diabetogenic action o f streptozotocin involves induction of apoptosis in pancreatic B-cells .