Transplantation of islet cell tumors induced by streptozotocin.

Mild and severe diabetes, confirmed by oral glucose tolerance tests, was induced in rats with streptozotocin, 50 and 65 mg/kg body weight, respectively. Insulin-secreting islet cell tumors produced by streptozotocin were transplanted underneath the kidney capsules of the diabetic rats. In 5 of 9 recipients given 50 mg/kg body weight of streptozotocin the mean blood glucose level 0. 5 hr following glucose loading significantly decreased 2 weeks after transplantation, although insulin responses remained flat and low. Concomitantly, daily urine volume and urine glucose decreased in these rats. The parameters of diabetes, however, returned toward the preoperative levels 4 weeks after the transplantation. On the contrary, none of the rats given 65 mg/kg body weight of streptozotocin showed any deviation of these parameters. Ten days after the operation visual observation revealed vascularization at trans-plantation sites and aldehyde-fuchsin-positive cells were seen in the peripheral portion of transplanted tumors. Transplants completely disappeared leaving white spots with fibrous tissue and cellular infiltration 29 days after the operation. The present study demonstrates that insulin-secreting islet cell tumors induced by streptozotocin possess the ability to reverse, though partially and temporarily, streptozotocin diabetes in the rat.