Epidermal growth factor binding is altered in pancreatic acini from diabetic rats

The effects of streptozotocin-induced diabetes on 125I-labeled epidermal growth factor (EGF) binding were studied in rat pancreatic acini. 125I-EGF binding was one-half maximal at 20 min, and maximal at 90 min. Saturation data revealed a decreased binding capacity in diabetic acini when compared with normal acini. Insulin, in vivo, normalized the decreased binding capacity. 125I-EGF internalization was also decreased in diabetic rat acini. Further, the inhibitory effect of cholecystokinin-octapeptide (CCK8) on cell-associated 125I-EGF radioactivity was significantly greater in diabetic than in normal rat acini. These findings suggest that insulin deficiency may lead to defective regulation of the exocrine pancreas by EGF.