[Studies on stable control of blood sugar by continuous administration of insulin through isolated intestinal loop]

Insulin (INS) has been known to be absorbed through the intestine in small amounts and to decrease blood sugar (BS) levels. However, stable control of BS has not been attained by intestinal intake of INS. To elucidate the possibility of a surgical approach to control hyperglycemic states, Thiry-Vella loops or upper jejunal loop fistulae were constructed in mongrel dogs in hyperglycemic states. Hyperglycemic states (around 400mg/dl) were induced by injecting streptozotocin. Lente insulin was administered every day to control hyperglycemia, except for the days for studies. As we confirmed that co-administration of aprotinin (TR) or nafamostat mesilate (FT) was necessary, to decrease BS by infusing INS into the intestinal loops, safe and effective dose levels were determined by series of preliminary infusion studies in the intestinal loops of diabetic dogs. By continuous infusion of these doses into the jejunal loop fistulae, a long term stable blood sugar control was attained in the diabetic dogs as long as 7 days. These results suggest that continuous infusion of INS with antiproteolytic adjuvants like TR or FT into the isolated small intestinal loop can control BS in hyperglycemic states.