Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Insulin may contribute to the increase in tubular reabsorption of phosphate during dietary phosphate restriction. Moreover, insulin is required for the stimulation of calcitriol under this experimental condition. To evaluate whether calcitriol plays a role in the antiphosphaturic effect of insulin during phosphate restriction, phosphate uptake was measured in brush border membrane vesicles (BBMVs) obtained from the following six experimental groups of rats: normal (0.8%)-phosphate diet for 1 wk, low (0.03%)-phosphate diet for 1 wk, normal-phosphate diet for 1 wk and streptozocin 48 h before the experiment, low-phosphate diet for 1 wk and streptozocin 48 h before the experiment, low-phosphate diet and streptozocin and exogenous insulin, and low-phosphate diet and streptozocin and exogenous calcitriol. BBMV phosphate uptake was higher in the nondiabetic rats on a low-phosphate diet than in the controls on a normal-phosphate diet. BBMV phosphate uptake was not different between diabetic rats on a normal-phosphate diet than in nondiabetic controls on the same diet. In contrast, BBMV was significantly lower in diabetic rats on a low-phosphate diet than in nondiabetic controls on the same diet. Exogenous insulin but not calcitriol restored the increase in BBMV phosphate uptake in diabetic rats on a low-phosphate diet. Plasma calcitriol levels were increased threefold in nondiabetic rats fed a low-phosphate diet. Streptozocin-induced diabetes abolished the adaptive increase in plasma calcitriol. Exogenous insulin and calcitriol administration to diabetic rats on a low-phosphate diet resulted in similar increases in plasma calcitriol levels. These results suggest that, during dietary phosphate restriction, insulin stimulates renal phosphate retention independently of its effect on calcitriol.
Diabetes 1991 Sep
PMID:Renal adaptation to dietary phosphate restriction in rats. Interactions with insulin and calcitriol. 193 21

BioBreed (BB) Wistar rats develop diabetes mellitus, which closely resembles the human disease, in 50% of progeny. Intestinal sucrase-alpha-dextrinase, a glycoprotein hydrolase of the enterocyte's brush border consisting of 140-kDa alpha-dextrinase and 125-kDa sucrase subunits, is essential for surface digestion of carbohydrate nutrients. Although its catalytic characteristics were found to be maintained in the diabetic state, the structure of the subunits, as compared with normal Wistar rats, was altered in the BB rat within 2 days of the onset of diabetes. Its capacity to react in a solid-phase immunoassay was reduced by 50%; when examined by 6% acrylamide electrophoresis, the sucrase subunit was increased in mass by 5 kDa and, in some BB rats, the dextrinase subunit was reduced by 5 kDa. Intact rats labeled intraintestinally with [35S]methionine displayed the alteration within 6 h of synthesis, indicating that nonenzymatic glycosylation could not account for the structural change. This mass change was not seen in streptozotocin-induced diabetes and was independent of the plasma glucose concentration or the degree of acidosis. Deglycosylation with peptide N-glycosidase indicated that the N-linked chains of the normal dextrinase subunit (11 kDa) have twice the mass of those in the BB rat (6 kDa) and that the sucrase subunit may have an increased mass of O-linked chains. Overall, these experiments point to changes in glycosylation as a mechanism of structural alteration in congenital diabetes. Despite persistence of the insulin-dependent diabetes, the subunit pattern eventually became indistinguishable from normal, but at differential rates (21 days and 35 days, respectively, for sucrase and dextrinase subunits).
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PMID:Sucrase-alpha-dextrinase in diabetic BioBreed rats: reversible alteration of subunit structure. 199 46

The localization of glycated protein in the kidney of diabetic rats was examined immunohistochemically with antiserum against glucitol-lysine. In diabetic rats the brush border and basement membrane of the proximal convoluted tubules were strongly immunoreactive with the antiserum but in control rats, only the brush border was weakly reactive. The immunoreactive tubules were more abundant in diabetic rats. No immunoreaction was found in any other structures in the kidney. Glycation of the proximal convoluted tubules may be an alteration in diabetic nephropathy.
Diabetes Res Clin Pract 1990 Mar
PMID:Immunohistochemical localization of glycated protein in diabetic rat kidney. 211 Dec 38

Alteration in dietary fatty acid composition produces changes in brush border membrane (BBM) fatty acid composition and changes in nutrient transport. Feeding a highly polyunsaturated fatty acid diet (P) reduces glucose uptake in diabetic rats to near control levels, whereas feeding a highly saturated fatty acid diet (S) enhances glucose uptake. Female Wistar rats were placed onto either a P or S diet for 5 weeks, injected with streptozotocin and continued on their respective diets for an additional 3 weeks. BBM were isolated, purified and extracted for analysis of fatty acyl constituents of phosphatidylcholine (PC) and phosphatidylethanolamine (PE). In jejunal and ileal BBM PC and PE, feeding S was associated with a decrease in total omega 6 fatty acids (18:2 omega 6), and an increase in the ratio of monounsaturated/saturated fatty acids as compared with animals fed P. In jejunal BBM PC and PE, the ratio of 18:2 omega 6/20:4 omega 6 was reduced in animals fed S as compared with those fed P. Diabetes was associated with fewer changes in BBM fatty acid composition in animals fed P as compared with those fed S. Feeding P to diabetic animals prevents the changes in BBM fatty acid composition observed when animals are fed S. Alterations in BBM lipid composition may be related to the enhanced permeability to glucose in animals fed S, while the similarity of BBM fatty acid composition in diabetic and control animals fed P may be related to the similar glucose uptake. The mechanisms controlling BBM lipid composition require further investigation, and may be important for the development of nutritional strategies for the control of diabetes.
Diabetes Res 1990 Aug
PMID:Dietary fat saturation alters diabetic rat brush border membrane phospholipid fatty acid composition. 213 88

Female Wistar rats were fed for 8 weeks a high polyunsaturated fatty acid diet (P) enriched with 18:2w6 and 18:3w3, or a high saturated fatty acid diet (S) enriched with 16:0, 18:0 and 18:1w9. There was a similar jejunal BBM fatty acid profile in phosphatidylcholine (PC) and phosphatidylethanolamine (PE) composition in animals fed P. However, feeding S altered the fatty acid composition of BBM phospholipids: for PC, feeding S increased total monounsaturated fatty acids (e.g. 18:1(9)) and reduced total polyunsaturated fatty acids, especially the total w6 fatty acids. For PE, feeding S increased only the total monounsaturated fatty acids. The ratio of monounsaturated/saturated fatty acids was increased for PC and PE. Fatty acid changes were more pronounced in the jejunal than ileal BBM. It is concluded that alterations in dietary fatty acid saturation: (a) influences intestinal BBM phospholipid fatty acid composition; (b) these changes are quantitatively and qualitatively different for PC and PE; and (c) changes are greater in the proximal than in the distal intestine. It is proposed that the previously reported diet-associated changes in active and passive intestinal transport are due at least in part to these alterations in the fatty acid composition in brush border membrane phospholipids.
Diabetes Res 1990 Aug
PMID:Alterations in dietary fatty acid composition alter rat brush border membrane phospholipid fatty acid composition. 213 89

A variety of tubular marker proteins, as compared to healthy controls, are excreted at an increased rate in the urine of patients with renal damage. Beside cytoplasmic glutathione-S-transferase and lysosomal beta-N-acetyl-glucosaminidase (beta-NAG) the majority of kidney-related urine proteins derives from membrane surface components of the most vulnerable proximal tubule epithelia, among them ala-(leu-gly)-aminopeptidase, gamma-glutamyl transpeptidase (GGT), the tubular portion of angiotensinase A, the major brush border glycoprotein 'SGP-240' and adenosine-deaminase-binding protein. Urinary tissue proteins, e.g. brush border (BB) microvilli, are immunologically identical with those antigens prepared from cell membranes of the human kidney itself. BB antigens are shed into the urine of patients with glomerulonephritis, interstitial nephritis, systemic diseases, e.g. systemic lupus erythematosus (SLE), diabetes mellitus and multiple myeloma, arterial hypertension, infectious diseases (malaria, AIDS) and after operations, renal grafting and administration of X-ray contrast media, aminoglycosides or certain cytostatics (cis-platinum). Tissue proteinuria of tubular proteins is determined by enzyme-kinetic or quantitative immunological assays applying either poly- or monoclonal antikidney antibodies. Clinical, ultrastructural and histochemical studies support the idea that both 'soluble' and high-molecular-weight membrane particles (vacuolar blebs, greater than 10(6) dalton) as well as microfilamental components of the epithelial cytoskeleton contribute to tubular 'histuria' which appears as a sensitive parameter in monitoring tubular damage under clinical conditions at a very early phase.
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PMID:Urinary proteins of tubular origin: basic immunochemical and clinical aspects. 225 76

The effect of progressive increases in intraluminal glucose concentration on proximal tubule sodium absorption was studied in normal and streptozotocin diabetic rats by microperfusion. Each tubule was perfused twice, with and without glucose added to the perfusion fluid. Net sodium and water absorption were markedly enhanced by 300-500 mg% intraluminal glucose in both normal and diabetic rats. Substituting the transported but nonmetabolized glucose analogue, alpha-methyl D-glucoside for glucose also resulted in marked stimulation of sodium absorption, whereas substituting bicarbonate and acetate for chloride in the perfusion solution inhibited the effect of glucose. These observations suggest that the stimulation of sodium absorption by glucose was mediated by the brush border Na/glucose cotransporter. Sodium concentration and osmolality were found to fall markedly to hypotonic levels when high glucose concentrations were in the perfusion fluid. This luminal hypotonicity may be an important driving force for proximal fluid absorption. In poorly controlled diabetes, high filtered glucose concentrations may lead to enhanced proximal sodium and water absorption, which could in turn contribute to volume expansion, hypertension, and renal hypertrophy.
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PMID:Progressive increases in luminal glucose stimulate proximal sodium absorption in normal and diabetic rats. 236 20

The urinary excretion of kidney-specific marker proteins before and 120 hours after intravenous injection of either high- or low-osmolar contrast media (CM; diatrizoate, iopamidol 370) was monitored in patients after digital vascular imaging. Inclusion criteria for the randomized clinical study in a total of 40 patients (15 women, 25 men; mean age, 64.5 years) were at least 50 years of age or diabetes mellitus with normal creatinine concentration in serum. Compared with the control period, the elimination of tubular indicator enzymes alanine aminopeptidase, gamma-glutamyltranspeptidase, alkaline phosphatase, as well as of glomerular localized angiotensinase A was significantly higher in all patients after injection of the CM. The most significant differences were observed after 48 hours. In contrast, lysosomal N-acetyl-beta-D-glucosaminidase activity in urine specimens reacted less clearly and appears to be a less sensitive parameter in assessing CM nephrotoxicity. Elimination of brush border as well as of glomerular marker proteins was significantly lower after intravenous injection of low-osmolar CM iopamidol 370 (832 mOsm/kg) than after meglumine diatrizoate 76 (2100 mOsm/kg). In all 40 patients a significant decrease in creatinine clearance was observed; however, patients receiving diatrizoate had a significant decrease in creatinine clearance (period 0 versus 24 to 48 hours after CM), whereas patients after administration of iopamidol had not. No difference was found between creatinine clearance after 48 hours of CM injection within both groups of CM. Due to noninvasive parameters of kidney damage nonionic, low-osmolar CM are less nephrotoxic in potential risk patients, and should be preferred to conventional CM.
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PMID:Nephrotoxicity of high and low osmolar contrast media: case control studies following digital subtraction angiography in potential risk patients. 256 16

The effects of chronic diabetes mellitus of 4-5 weeks duration on the potential difference across the brush border membrane of rat small intestine (Vm) and on Na+-dependent uptake of D-glucose by jejunal brush border vesicles have been studied. Diabetes increased Vm in the jejunum from a mean value of -47.2 mV in control tissue to -57.4 mV in diabetic tissue (P less than 0.001) but was without effect on ileal Vm. Measurements of Vm during ion-substitution experiments revealed that the conductance of Na+ of the jejunal brush border was reduced by diabetes, whilst K+ and Cl- permeabilities were unaltered. Uptake studies using brush border vesicles and an Na+-electrochemical gradient showed that diabetes caused a 56% increase in the initial rate of uptake of D-glucose but was without effect on the peak to equilibrium ratio. Taken together, data from these two studies suggest that the lower Na+ permeability of the brush border in diabetes enhances the electrical and chemical driving force for active Na+-dependent uptake of glucose by reducing glucose-independent movement of Na+ across this membrane. Finally, the possible humoral factors involved in this response to diabetes are discussed.
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PMID:Diabetes mellitus and the sodium electrochemical gradient across the brush border membrane of rat intestinal enterocytes. 260 55

The specific activities of membrane-bound maltase (alpha-D-glucoside glucohydrolase, EC 3.2.1.20) in isolated brush border membranes (BBMs) of alloxan-induced diabetic, glucose-infused and maltose-infused rabbits were 30%, 140% and 160%, respectively, of those of control rabbits. Differences in the relative activities of trehalase (EC 3.2.1.28), another disaccharidase, in these groups were similar but less marked. However, the activities of two other marker enzymes of the brush border, alkaline-phosphatase and gamma-glutamyl transpeptidase, were similar in the 4 groups of rabbits. The decreases in the activities of the two disaccharidases were due to changes in the Vmax values of the enzymes without change in their Km values for maltose and trehalose. The maltase activities in the 4 groups showed similar dependences on Tris-HCl, KCl and NaCl. The electrophoretic profiles of the BBMs of the 4 groups on SDS-polyacrylamide gel showed slight differences. From these results, we conclude that diabetes, glucose infusion and maltose infusion probably change the concentrations of active enzymes in the BBM of the kidney in rabbits.
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PMID:Comparisons of maltase activities in kidney brush border membranes from normal, diabetic, glucose-infused and maltose-infused rabbits. 266 45


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