hydroxylysine and Diabetes-Mellitus

Topics: Animals; Antibodies; Basement Membrane; Blood Glucose; Collagen; Diabetes Mellitus; Fibrin; Glycoproteins; Humans; Hydroxylysine; Kidney Glomerulus; Permeability

The nonenzymatic glycation of glomerular basement membranes (GBMs) from 14 diabetic and 19 nondiabetic human subjects was determined after boronic acid affinity and high-performance cation-exchange chromatography of their NaB[3H]4-reduced ketoamine adducts. The glucitol-lysine (Glc-Lys) and the glucitol-hydroxylysine (Glc-Hyl) content of diabetic GBM was found to be about twofold higher than that of nondiabetic samples (P less than .001). The content of these glycated amino acids did not correlate with age over the range examined (20-91 yr) or with the length of disease in diabetic subjects (2-16 yr). However, analyses of Glc-Lys and Glc-Hyl in calf and adult bovine GBM and lens capsules indicated that the levels of these glycated amino acids were several times greater in basement membranes from older animals. We also observed that guanidine-insoluble collagen of bovine GBM is more extensively glycated (approximately 4-fold) than primarily noncollagenous proteins that are extracted by this reagent. In all of the basement membranes examined, the percentage of glycation of lysine was greater than of hydroxylysine. Characterization of the components released by alkaline hydrolysis indicated that O-glycosylated hydroxylysine residues are nonenzymatically N-glycated to the same extent as those without an enzymatically attached carbohydrate unit. Our study indicates that more than a hundred times as many hydroxylysine residues are enzymatically glycosylated in human and bovine GBM as those containing the nonenzymatically formed ketoamine adduct.

Topics: Adult; Aged; Aged, 80 and over; Animals; Basement Membrane; Cattle; Chromatography, High Pressure Liquid; Diabetes Mellitus; Glycosylation; Humans; Hydrolysis; Hydroxylysine; Kidney Glomerulus; Lens Capsule, Crystalline; Lens, Crystalline; Lysine; Middle Aged

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

A recent report claimed that an amine in human skin (believed to be pyridinoline) was deficient in specimens from patients with abdominal aortic aneurysms (AAA). Further studies suggest that this work was erroneous in two respects. First, the amine has been isolated and partially characterized; the major component of the peak of interest is a deoxyanalogue of pyridinoline. It may be a collagen cross-link of some biologic importance, because it is not detectable in skin from a patient with Marfan's syndrome. Second, further studies in an additional 19 patients with AAA and an additional 13 controls suggest that this amine is abnormally abundant in skin from patients with AAA. This difference cannot be accounted for by any potential source of artifact that has been traceable. The effects of age, diabetes, sex, race, site of biopsy, and source of specimen (autopsy versus surgery) have been studied; none of these variables can account for the high ratio of pyridinolines to hydroxylysine found in skin from patients with AAA.

Topics: Adolescent; Adult; Aged; Amino Acids; Aorta, Abdominal; Aortic Aneurysm; Chromatography, High Pressure Liquid; Diabetes Mellitus; Female; Humans; Hydroxylysine; Male; Middle Aged; Skin

To study the glycosylation of glomerular basement membrane collagen (GBMC) in diabetes, kidneys were obtained at autopsy from 5 patients with insulin-requiring diabetes of long duration and diabetic complications, and from 5 control subjects. Glomeruli were prepared by sieving and collagen was isolated by limited pepsin proteolysis followed by salt precipitations. Amino acid analyses of the collagen preparations, after acid hydrolysis, indicated a composition consistent with that of type IV collagen. No differences in the relative contents of various amino acids, and in particular, 3-hydroxyproline, 4-hydroxyproline and hydroxylysine, were noted between diabetic and control samples. Non-enzymatic glucosylation was assessed by measuring hexose in ketoamine linkage with thiobarbituric acid after conversion to 5-hydroxymethylfurfural. In 4 of the 5 patients studied, glucosylation values exceeded the mean +2 S.D. of the controls; in the fifth subject glucosylation was in the high normal range. No correlation between the severity of diabetes and hexose content of GBMC was noted, however. In further studies, enzymatic glycosylation of GBMC was assayed after alkaline hydrolysis by separation of glucosylgalactosyl-O-hydroxylysine, galactosyl-O-hydroxylysine, and unsubstituted hydroxylysine in an amino acid analyzer. No differences in the relative contents of hydroxylysine-O-glycosides were evident between diabetic and control GBMC. The results suggest that non-enzymatic glucosylation, but not glycosylation catalyzed by collagen glucosyl and galactosyl transferases, is increased in diabetes. The increased carbohydrate content of collagen may lead to decreased turnover and/or excessive accumulations of basement membrane collagen thus contributing to the vascular complications of diabetes.

Topics: Adult; Aged; Amino Acids; Basement Membrane; Carbohydrate Conformation; Collagen; Diabetes Mellitus; Female; Glucose; Hexoses; Humans; Hydroxylysine; Kidney Glomerulus; Male; Middle Aged

In order to study the metabolism of collagenous proteins in diabetes mellitus, urinary excretion of O-hydroxylysylglycosides, a characteristic component of collagenous protein, was determined in diabetics and controls. There was no significant correlation between urinary excretion rate of O-hydroxylysylglycosides and age (r = -0.40 for diabetics and r = -0.15 for control). In 16 age-matched pairs, urinary excretion of O-hydroxylysylglycosides was less in diabetics than in control (0.78 +/- 0.18 (mean +/- S.D.) mu moles/m2 body surface x hr versus 0.92 +/- 0.18 mu moles/m2 body surface x hr, p less than 0.05). This results suggests that catabolism of collagenous protein decreases in diabetics.

Topics: Adolescent; Adult; Aged; Diabetes Mellitus; Glycosides; Humans; Hydroxylysine; Middle Aged

A method was established to isolate the glomeruli from the kidney fixed in formaldehyde. O-Hydroxylysylglycosides and hydroxyproline in the isolated glomeruli from the kidney of normal subjects, diabetics and subjects with chronic glomerulonephritis were measured on the alkaline hydrolyzate of the glomeruli. O-Hydroxylysylglycosides in 1000 glomeruli were 9.42 +/- 2.68 nmoles (mean +/- S.D.) for controls, 12.92 +/- 7.36 nmoles for diabetics and 12.54 +/- 4.62 nmoles for subjects with chronic glomerulonephritis. Hydroxyproline in 1000 glomeruli from control, diabetics and subjects with chronic glomerulonephritis was 43.0 +/- 10.7, 82.0 +/- 39.3 and 52.1 +/- 21.3 nmoles, respectively. Hydroxyproline in the hyalinized glomeruli from diabetics was 123.3 +/- 22.4 nmoles/1000 glomeruli, and significantly increased in comparison with that in the glomeruli from chronic glomerulonephritis or control subjects.

Topics: Adult; Aged; Chronic Disease; Diabetes Mellitus; Glomerulonephritis; Glycoproteins; Humans; Hydroxylysine; Hydroxyproline; Kidney Glomerulus; Middle Aged

Since the biochemical composition of the diabetic glomerular basement membrane is still a controversial area, a study was carried out using kidneys from seven diabetic and seven nondiabetic subjects. In diabetic membranes, the glycine, hydroxylysine, glucose, galactose, and hydroxylysine-linked disaccharide unit content was increased together with a decrease in the half-cystine and sialic acid content. These findings support the view of a biochemical alteration in the human diabetic glomerular basement membrane.

Topics: Adult; Aged; Amino Acids; Basement Membrane; Carbohydrate Metabolism; Cystine; Diabetes Mellitus; Female; Glucosamine; Humans; Hydroxylysine; Kidney Glomerulus; Lysine; Male; Middle Aged

To study the effect of streptozotocin induced diabetes on glomerular basement membrane (GBM) synthesis, an isolated rat glomerular preparation has been developed, and its metabolic properties have been defined. The chemical composition of normal rat GBM isolated from this preparation closely resembles human GBM. Incubation with [U-14C] lysine leads to prompt incorporation of label into GBM and the subsequent appearance of labeled hydroxylysine. A 1-h lag before detection of labeled hydroxylysine in GBM suggests a delay in the release of GBM precursors. Significantly lower counts appeared in the nondialyzable fraction of the medium than in insoluble GBM during pulse-chase experiments, and labeled hydroxylysine accounted for a lower portion of the total counts in the medium (0.85%) than in the GBM (1.98%). Isolated glomeruli were prepared from streptozotocin diabetic rats of 4-6 wks duration. After incubation with [ U-14C] lysine recovery of label in diabetic GBM (88.98+/-8.26 nmol/g GBM) did not differ from age matched controls (82.52 +/- 8.26 nmol/g GBM). In pulse-chase experiments recovery of label in hydroxylysine of diabetic GBM (o.473 +/- 0.082 nmol/g GBM) did not differ from age matched controls (0567+/-0.065 nmol/g GBM). These findings indicate normal rates of GBM synthesis and hydroxylation of lysine residues in animals with streptozotocin diabetes.

Topics: Amino Acids; Animals; Basement Membrane; Diabetes Mellitus; Disease Models, Animal; Hydroxylysine; In Vitro Techniques; Kidney Glomerulus; Lysine; Rats; Streptozocin

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

Current evidence indicates that a hydroxylysine-rich glycoprotein may be of importance in the structural organization and accumulation of glomerular basement membrane in the diabetic state. To further evaluate the role of insulin deficiency in renal glycoprotein synthesis, the effect of experimental diabetes on the incorporation and hydroxylation of 14C-lysine by cell-free systems prepared from rat renal cortex was examined. Microsomal protein synthesis was increased in diabetic preparations, but the rise in renal cortical collagen synthesis relative to total protein synthesis was greater. These changes were not duplicated by the addition of a mixture of unlabeled amino acids or hydroxylation cofactors to incubations with preparations from normal animals.

Topics: Amino Acids; Animals; Cytosol; Diabetes Mellitus; Hydroxylysine; Kidney Cortex; Lysine; Microsomes; Pancreatectomy; Protein Biosynthesis; Rats; Rats, Inbred Strains

Topics: Acetylation; Adult; Aged; Amino Acids; Antigen-Antibody Complex; Autoanalysis; Basement Membrane; Cystine; Diabetes Mellitus; Fluorescent Antibody Technique; Galactose; Glucose; Humans; Hydrolysis; Hydroxylysine; Immunoglobulin G; Kidney Diseases; Kidney Glomerulus; Lupus Erythematosus, Systemic; Lysine; Mannose; Middle Aged; Proteinuria; Staining and Labeling

Topics: Basement Membrane; Cystine; Diabetes Mellitus; Disaccharides; Fucose; Galactose; Glycine; Glycoproteins; Hexosamines; Humans; Hydroxylysine; Hydroxyproline; Kidney Glomerulus; Mannose; Microbial Collagenase; Neuraminic Acids; Peptides; Pronase; Tyrosine; Valine

Topics: Amino Acids; Animals; Basement Membrane; Carbohydrate Metabolism; Chromatography, Gel; Diabetes Mellitus; Diabetes Mellitus, Experimental; Electrophoresis, Disc; Electrophoresis, Polyacrylamide Gel; Glucosyltransferases; Glycoside Hydrolases; Humans; Hydroxylysine; Insulin; Kidney Glomerulus; Lysine; Polysaccharides

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

Topics: Animals; Basement Membrane; Carbon Isotopes; Collagen; Cytosol; Diabetes Mellitus; Hydroxylation; Hydroxylysine; Hyperglycemia; Kidney Glomerulus; Lysine; Pancreas; Pancreatectomy; Peptide Biosynthesis; Protein Biosynthesis; Rats; Rats, Inbred Strains; Subcellular Fractions; Tritium