The Biological Properties of Human Insulin

Abstract

ABSTRACT. Semisynthetic human insulin (Novo) was compared with porcine insulin with regard to absorption from subcutaneous depots, blood glucose control and plasma insulin concentrations in patients, and the binding to insulin receptors of porcine and human origin. The binding affinities of semisynthetic human insulin and porcine insulin were identical with human erythrocyte receptors and receptors on porcine hepatocytes. The subcutaneous absorption of semisynthetic human and porcine 125 I‐labelled insulin both of soluble and lente type was identical. The metabolic control study was performed as a double‐blind crossover study in eight type I diabetics. They received semisynthetic human insulin and porcine insulin (of soluble as well as lente type) for 10 days each, the last 7 days in each period being the observation period. Blood glucose concentration was measured 9 times per 24 hours. No statistically significant differences were found between mean blood glucose levels at the 9 samplings or in the overall mean blood glucose concentration. Further, the blood glucose control was evaluated as a function of time by a computerized method for time series analysis of a complex dynamic system. This method described adequately each blood glucose value as a linear function of the immediately preceding blood glucose value and that measured 24 hours before. No difference was found between human and porcine insulin when the blood glucose control was assessed by this method. Plasma concentrations of total insulin (IRI) and free IRI before and 3 hours after the morning insulin injection were identical in the two treatment periods. It is concluded that human and porcine insulin can be interchanged in the treatment of diabetics without changing the dose.