hydroxylysine and Diabetic-Nephropathies

Diabetic microangiopathy, particularly as seen in the renal glomerulus, is characterized by morphological and biochemical alterations of the capillary basement membrane. Observations from a number of disciplines have indicated that the microvascular disease is not a separately inherited entity but a true consequence or "complication" of insulin deficiency. An evaluation of the biochemical events which could be responsible for the basement membrane lesions of diabetes indicates that the hyperglycemia or plasma somatotropin elevation of this disease alone, or in combination, may play an important role.

Topics: Animals; Basement Membrane; Carbohydrate Metabolism; Collagen; Diabetic Nephropathies; Glucose; Glycoproteins; Growth Hormone; Hemoglobins; Hexosyltransferases; Histocytochemistry; Humans; Hydroxylysine; Insulin; Kidney Glomerulus; Nephrosclerosis; Rats; Sorbitol

Topics: Amino Acids; Basement Membrane; Diabetic Angiopathies; Diabetic Nephropathies; Glycoproteins; Humans; Hydroxylysine; Kidney Glomerulus; Macromolecular Substances; Models, Chemical

Amino acid analysis was carried out on the acid hydrolyzate of the glomeruli isolated from the kidneys of 19 nondiabetic and 21 diabetic autopsy subjects. The glomeruli isolated from the diabetics were found to have a significant increase in their contents of amino acids such as hydroxyproline, glycine and hydroxylysine, when compared with nondiabetic controls. These changes were detected already in the diabetic cases with no apparent histological change, and were prominent in the glomeruli which had nodular lesion. A linear relationship was evident between the contents of hydroxyproline and hydroxylysine in the glomeruli isolated from all 40 subjects studied (y = 9.50 + 4.88x, r = 0.918, p less than 0.001). The values for the diabetic glomeruli showing diffuse lesion and nodular lesion scattered continuously along the same line. These results suggest that chemical character is almost same in the diabetic glomeruli with either diffuse lesion or nodular lesion.

Topics: Aged; Amino Acids; Collagen; Diabetes Mellitus; Diabetic Nephropathies; Female; Humans; Hydroxylysine; Hydroxyproline; Kidney Glomerulus; Lysine; Male; Middle Aged; Proline

Glomerular basement membrane (GBM) and tubular basement membrane (TBM) were prepared from human kidneys of diabetics and non-diabetics, and their chemical composition was compared. GBM from diabetics contained a larger amount of hydroxyproline than that from non-diabetics, and smaller amounts of half-cystine, glucose, mannose and sialic acid. On the other hand, TBM from diabetics contained larger amounts of hydroxylysine, methionine, galactose, hexosamine and phospholipid phosphorus than non-diabetics, and smaller amounts of half-cystine, valine, leucine, lysine and histidine. No significant difference was observed in the contents of other components examined in this study between the corresponding membrane obtained from diabetics and non-diabetics. The observed changes may be due to alteration of the tissues in diabetes mellitus.

Topics: Adult; Aged; Amino Acids; Basement Membrane; Carbohydrates; Cystine; Diabetes Mellitus; Diabetic Nephropathies; Female; Humans; Hydroxylation; Hydroxylysine; Kidney Glomerulus; Kidney Tubules; Lysine; Male; Middle Aged; Phospholipids

Topics: Amino Acids; Animals; Basement Membrane; Carbohydrate Metabolism; Collagen; Diabetes Mellitus; Diabetic Nephropathies; Fucose; Galactosamine; Galactose; Glucosamine; Glucose; Glycine; Hexoses; Humans; Hydroxylysine; Hydroxyproline; Kidney Glomerulus; Mannose; Microscopy, Electron; Neuraminic Acids