Concentration of Porcine Proinsulin-Like Material in Plasma of Insulin-Treated Diabetics in Relation to Purity of Insulin Preparations

Abstract

Porcine Proinsulin-Like Material (P-PLM) was determined in plasma from 25 juvenile diabetics previously treated for more than six years with crystalline porcine insulin and again after 2-2 œ years subsequent treatment with highly purified porcine insulin. As P-PLM in insulin preparations was reduced from 7 mmol/mol insulin to 0.1 mmol/mol insulin, so plasma concentrations of P-PLM were reduced from mean 166 pmol/1 (range 34-428) to mean 27 pmol/1 (range 13-64) on the same insulin dose. During the same period, the insulin-binding capacity of plasma showed a decrease.