Ultrastructure of proteoglycans in human renal arteries from end stage renal disease

Although glycosaminoglycans, particularly proteoglycans, have been characterized biochemically in normal and diseased arteries, little is known regarding their ultrastructural characteristics in human arteries. The observations reported here were made in renal arteries from nephrectomy specimens from patients with endstage kidney disease and hypertension. By light microscopy, the diffusely thick intima is characterized by small, slender smooth muscle cells embedded in a finely fibrillar, strongly alcian-blue positive, intercellular matrix. Ultrastructurally, there is a loose meshwork of collagen fibrils, elastic units and abundant fibrillogranular units staining strongly with ruthenium red and identified as proteoglycans. These consist of ovoid or diamond-shaped electron-dense granules about 300-500 A in diameter, having fine filamentous processes.