Effects of glucagon administration on microcirculation and blood rheology

Abstract

It has been reported that some rheologic abnormalities are associated with diabetes. However, it is difficult to realize the condition of microcirculation in men. We developed an intra‐vital video‐microscopic system (IVVMS) to observe microcirculation directly on the bulbar conjunctiva. Using this system, we investigated the effect of intravenous glucagon administration on microcirculatory parameters such as the internal diameter of venules, flow velocity and flow volumes in diabetic patients. Blood viscosity and rheology factors were also examined before and after glucagon administration. The time required for erythrocytes to pass through pores of 5 $\mu$ m diameter, as well as whole blood viscosity were decreased significantly after glucagon administration. Flow volumes of venules were increased significantly by glucagon. Leukocyte counts, platelet counts and fibrinogen did not change after glucagon administration. However, plasma glucose, insulin, C‐peptide and cyclic‐AMP were increased. In conclusion, glucagon administration improved blood fluidity and modified the microcirculation in patients with diabetes mellitus.