[Studies on urolithiasis. The histochemistry of the kidney tissues and stones from patients with urolithiasis]

Abstract

In this study, 17 kidney tissue specimens and 29 renal stones were obtained from patients with urolithiasis. Control kidney specimens were dissected from 7 individuals not suffering from urolithiasis. The tissue specimens were fixed with 1% cetylpiridinium chloride (CPC) in 10% formalin (for 24 hours at room temperature). Then the kidney tissue specimens were embedded in paraffin and stained with hematoxylin-eosin for general observation as well as histochemically for demonstration of complex carbohydrates. Also, stone specimens were embedded in epon and thin sections made by the mineral polishing specimen preparation, and stained along with the kidney tissues. For identifying individual acidic and neutral carbohydrates, the enzyme digestion was performed for some tissue sections prior to histochemical staining. The stone-forming kidney tissues, normal kidney tissues and urinary stones (calcium oxalate, mixed, struvite) contained some glycosaminoglycans and neutral glycoproteins, but uric acid stones and cystine stones did not. The results of digestion with enzymes indicated that calcium oxalate stone-forming kidney tissue contains heparitin (heparan) sulfate; mixed stone-forming tissue contains sialic acid, hyaluronic acid, chondroitin sulfate A, B, C and heparitin (heparan) sulfate; struvite stone-forming tissue contains sialic acid, hyaluronic acid, chondroitin sulfate A, C and heparitin (heparan) sulfate; and cystine stone-forming tissue contains sialic acid, chondroitin sulfate A, C and heparitin (heparan) sulfate. The stone organic matrix is classified into the amorphous and stratiform types. The amorphous type matrix contains chondroitin sulfate A, B, C and heparitin (heparan) sulfate, and the stratiform type matrix also contains sialic acid and hyaluronic acid. The stone-forming kidney tissues, normal kidney tissues and stones (calcium oxalate, mixed, struvite) contain an appreciable amount of alpha-D-glucose, alpha-D-mannose and beta-D-galactose, but the uric acid stones and cystine stones do not contain sugar residues. Since the specific glycosaminoglycan composition differed for kidneys of different mineral content and stones of different morphological type, we believe that some glycosaminoglycans in kidneys and amorphous type matrix might play the role of a nucleating agent, and that a stratiform type matrix encourages stone enlargement.