HUMAN INSULIN ABSORPTION FROM THE INTESTINE IN DIABETIC RATS

The ability of human insulin to produce hypoglycemia in streptozocin-d iabetic rats (average weight 500 g) was investigated. A simple solutio n of human insulin (insulin in hypotonic buffer solution) was administ ered intraduodenally. Rats received a dose of insulin of either 200 U/ kg, 400 U/kg, or 600 U/kg. The hypoglycemic response was most signific ant when 600 U/kg solution of insulin was administered. The 200 U/kg d ose was of two forms; one form was a solution of insulin with a concen tration of 25 U/ml, 4 ml, and the other was a solution of insulin with a concentration of 50 U/ml, 2 ml. The dose of 25 U/ml, 4 ml produced a more significant hypoglycemic response than that of 50 U/ml, 2 ml. C arrier-insulin systems were also introduced intraduodenally in strepto zocin-diabetic rats. The results indicate that the carrier systems wit hout insulin had glucogenic effect. Despite this glucogenic effect, ca rrier-insulin systems at 200 U/kg dose were as effective as that of 60 0 U/kg of insulin solution. We conclude that insulin absorption from t he intestine can cause a significant hypoglycemic state if given in a large enough dose, even without the presence of other absorption enhan cers in the dosage form.