Chronic hyperglycemia is a common feature of all forms of diabetes mellitus and may contribute greatly to the increase in the incidence of atherosclerosis. It has been demonstrated that increasing arterial permeability to the macromolecules can cause low-density lipoproteins (LDLs) to infiltrate and accumulate in the intima. This event is crucial for developing the plaques in the arterial wall. in this study, we use Evans blue to study the permeability of arterial endothelium in the streptozotocin (STZ)-induced hyperglycemic rats. We also use colloidal gold-labeled LDL to investigate in situ the distribution of LDL in the aortic intima of hyperglycemic rats.

The hyperglycemia was induced in male Sprague-Dawley rats (7 weeks) by a single intraperitoneal injection of streptozotocin (60 mg/kg). The blood glucose concentration and hemoglobin glycation were measured once in every week. The uptake of drinking water is monitored in the regular time interval. After 3 months into the experiment, ten hyperglycemic and control rats were anesthetized.