No Effect of Aprotinin (Trasylol) on Degradation of Exogenous and Endogenous Glucagon in Human, Mouse and Rat Plasma

Abstract

Traditionally, aprotinin (Trasylol™) has been added to plasma samples prior to glucagon analysis. However, the evidence for the need of aprotinin is sparse and based on results obtained when radioimmunoassay (RIA) techniques were still in their infancy. Using RIAs directed against both the C-terminus and a mid-region of glucagon, we challenged the classical view that aprotinin is necessary. Glucagon concentrations in pools of human, mouse and rat plasma (n=30, 25 and 16 of each, respectively) with and without addition of increasing amounts of exogenous glucagon (5, 10, 20, 40 and 60 pM) were similar irrespective of whether or not aprotinin had been added. To investigate whether individual variation occurs in human samples, we measured plasma from 20 patients with gastrointestinal diseases and 20 healthy subjects with or without addition of aprotinin. Again, measured amounts of glucagon, endogenous or added, were not affected by the presence of aprotinin. The effect of aprotinin, present at blood sampling or added later (30 and 60 minutes), on endogenous glucagon values was investigated in T2DM patients (n=5), before and after insulin-induced hypoglycemia. There were no differences between the four treatments. In conclusion, we found no support for use of aprotinin for prevention of glucagon degradation.