[Study on the capillary permeability of myocardium in diabetic rats]

The alteration of myocardial capillary permeability (MCP) in experimental diabetic rat was investigated by using cationic ferritin as a tracer. Diabetes was induced by injection of streptozocin (70mg/kg b.w.ip.). Vehicle injected, age and body weight-matched rats were served as the controls. The myocardial tissue was examined by the end of 2,7, and 9 months or even longer after diabetes induction. Results showed that (1) MCP was significantly increased in diabetic rats in comparing with that of the controls; (2) The increase of permeability became more pronounced with prolongation of the course of diabetes; and (3) the increase of MCP preceded the capillary basal laminar thickening demonstrated by electron microscopy. These findings suggest that increased MCP may play a role in the pathogenesis of basal laminar thickening and myocardial complications in diabetic state.