REMODELING OF RENAL ARTERIOLES IN SPONTANEOUSLY HYPERTENSIVE RATE PRIOR TO AND DURING ESTABLISHED HYPERTENSION

Objective To investigate the relationship between morphological remodeling of renal arterioles and etiology of hypertension. Methods Under dilated conditions, the morphometry of the renal arterioles, and the widths of medial vascular smooth muscle cells (VSMC) and intercellular space were studied on kidney slices by light microscope and electromicroscope combining computer assistant image analysis system in 4 and 16 weeks old SHR.Results The morphological changes of the renal arterioles in 4 weeks old SHR were not significant compared with age matched WKY. In 16 weeks old SHR, the wall thickness and ratio of wall thickness to inner diameter of the renal arterioles in 20 to 50 μm outer diameter changed but not the wall area. All the above three parameters increased significantly in renal arterioles of 50 to 200μm outer diameter. The widths of VSMC and intercellular of renal arterioles in 16 weeks old SHR were greater than that in age matched WKY. Conclusions After the establishment of hypertension in SHR, the remodeling of the renal arterioles is occurred, in which the renal arterioles less than 50μm outer diameter is perhaps due to the rearrangement of medial VSMC, but the renal arterioles more than 50μm outer diameter is due to proliferation of the medial VSMC and increase of the extracellular matrix.