[Pathogenesis and hemodynamic significance of veno-arterial reaction in diabetic microcirculation disorders]

In human diabetes mellitus, functional microangiopathy starts with venule dilatation, the cause of which is unknown. The results of comparative measurements of animals with alloxan diabetes verify also an increase in the arterio-venous calibre relation. As studied vital-microscopically, these alterations are due to venule congestion and passive dilatation as a consequence or red cell aggregation and an increase in the viscosity of blood. The increase of the flow resistance on the postcapillary side depends only on rheological but not on nervous-humoral factors, which leads by means of a veno-arterial reaction to increased constrictions of the arterioles.