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)

The effect of L-arginine on the arginase activity and polyamine levels was studied in the pancreas of normal and diabetic rats (120 mg/kg alloxan, i.v.). Four groups were formed (10 male adults per group). I-Control-0.154 M NaCl. II-Diabetic-0.154 M NaCl (96 h after alloxan). III-Control plus 10 mM L-arginine IV-Diabetics plus 10 mM L-arginine. Rats were sacrificed 20 min after L-arginine injection. Glucose in serum and dry weight, proteins, arginase activity and polyamines (HPLC) in pancreas were measured. Higher ratio mg protein/mg dry weight and arginase induction was observed for groups III and IV. Putrescine was low as a consequence of diabetes but restored with L-arginine. The concentrations of spermidine and spermine were lower. These results may suggest that arginine is metabolized to putrescine in the pancreas and that polyamines may be utilized in regenerating processes or for recovering the endocrine pancreatic function.
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PMID:Effect of L-arginine on pancreatic arginase activity and polyamines in alloxan treated rats. 148 95

Arginase activity is elevated in livers of diabetic animals compared to controls and there is evidence that this is due in part to increased specific activity (activity/mg arginase protein). To investigate the molecular basis of this increased activity, the physicochemical and kinetic properties of hepatic arginase from diabetic and control mice were compared. Two types of arginase subunits with molecular weights of 35,000 and 38,000 were found in both the diabetic and control animals and the subunits in these animals had similar, multiple ionic forms. Kinetic parameters of purified preparations of arginase for arginine (apparent Km and Vmax values) and the thermal stability of these preparations from diabetics and controls were also similar. Furthermore, no difference was found in the distribution of arginase activity among different subcellular liver fractions. Separation of basic and acidic oligomeric forms of arginase by fast-protein liquid chromatography resulted in a slightly different distribution of activity among the forms in the normal and diabetic group. The apparent Km values for Mn2+ of the basic form of the enzyme were 25 and 33 microM for the enzyme from normal and diabetic animals, respectively; for acidic forms, for which two apparent Km values were measured, the values were 8 and 197 microM for arginase from controls and 35 and 537 microM from diabetics. These results indicate that in diabetes, while no marked changes in the physicochemical characteristics of arginase are obvious, some changes are found in the interaction of arginase with its cofactor Mn.
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PMID:Comparison of biochemical properties of liver arginase from streptozocin-induced diabetic and control mice. 280 20

The regulation of hepatic arginase (EC 3.5.3.1) activity was studied in diabetic rats fed ad libitum. Arginase activity in liver cytosol increased 2 to 3 days after injection of streptozotocin into rats and remained elevated (maximally 1.7-fold) 13 days postinjection. Radioimmunoassays indicated, however, that the amounts of immunoreactive arginase protein in livers of control and diabetic rats were similar. The specific activity of purified preparations of arginase from diabetic rats was approximately 1.5-fold higher than that from control rats. Manganese, a cofactor for arginase, was elevated by 4 days post-streptozotocin injection and remained elevated (maximally 1.6-fold) for at least 13 days. Most of the manganese in control and diabetic liver cytosols was associated with macromolecules and eluted with arginase activity upon gel filtration. These data establish that the enhanced arginase activity observed in diabetes is coincident with elevated cofactor concentration but not with elevated enzyme protein concentration.
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PMID:Elevated manganese concentration and arginase activity in livers of streptozotocin-induced diabetic rats. 640 84

The effects of a high fat diet (30% (w/w) corn oil) on chronic streptozotocin-diabetic rats were investigated at the whole body level and at the enzyme level. The diet caused significant decreases in the extent of polydipsia (66% decrease), polyphagia (49%), polyuria (67%) and glycosuria (70%). The activities of selected hepatic enzymes from the glycolytic, gluconeogenic, ureogenic and lipogenic clusters were determined. The fat diet caused significant decreases (range: 47 to 54%) in the activity of the ureogenic enzymes carbamyl phosphate synthetase, ornithine transcarbamylase and arginase; had no effect on the glycolytic enzymes glucokinase, hexokinase and pyruvate kinase; partially decreased the diabetes-induced elevated activities of the gluconeogenic enzymes phosphoenolpyruvate carboxykinase (63% decrease), serine dehydratase (90%), alanine aminotransferase (31%) and aspartate aminotransferase (65%), and partially reversed the activity of one lipogenic enzyme, ATP citrate lyase.
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PMID:The effects of a high fat diet on chronic streptozotocin-diabetic rats. 692 68

There is a significant increase in four of the urea cycle enzymes in liver from hypothyroid rats, arginase alone showed an opposite trend; these changes are reversed by physiological doses of thyroxine; hyperthyroidism results in a significant decrease in ornithine transcarbamoylase activity. The pattern of change in thyroidectomized and alloxan-diabetic rats showed marked similarities in respect to urea cycle and ornithine-metabolizing enzymes which are discussed in the light of the common feature of hypoinsulinism of diabetes and depressed response to insulin in hypothyroidism. The profile of ornithine-metabolizing enzymes is consonant with the decreased protein synthesis and turnover in hypothyroidism.
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PMID:Regulation of pathways of ornithine metabolism. Effects of thyroid hormone and diabetes on the activity of enzymes at the "ornithine crossroads' in rat liver. 721 33

Arginine metabolism via nitric oxide (NO) synthase and other pathways was studied in coronary endothelial cells (EC) from the spontaneously diabetic BB rat, an animal model of human type I diabetes mellitus (IDDM). EC were prepared from insulin-treated diabetic BB (BBd) and non-diabetes-prone BB (BBn) rats. Basal NO synthesis was studied in EC cultured for 48 h in medium containing 0.4 mM L-arginine. At the end of the culture period, the medium was analyzed for nitrite and nitrate (two major end stable oxidation products of NO), and the cells were used to determine arginine uptake and metabolism and the activities of some arginine-degrading enzymes. For studies of arginine metabolism, cells were incubated at 37 degrees C for 1 h in Krebs-Henseleit bicarbonate buffer (pH 7.4) containing 1 mM L(-)[1-14C]arginine or L(-)[1-14C]ornithine. The rates of production of nitrite plus nitrate by BBd EC were only 15% of those of BBn cells. This impaired NO synthesis in BBd EC was not due to alterations in arginine uptake, NO synthase activity, or intracellular arginine concentrations but might have resulted from a limited intracellular availability of cofactors of NO synthase. In addition to the arginine-NO pathway, arginine was found to be metabolized to urea, ornithine, and, to a much lesser extent, CO2 via arginase and ornithine aminotransferase. The activities of arginase and the formation of ornithine and urea from arginine were decreased by 90% in BBd compared with BBn cells. These results, coupled with the reduced NO synthesis, indicate metabolic defects in arginine metabolism in BBd EC.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Impaired arginine metabolism and NO synthesis in coronary endothelial cells of the spontaneously diabetic BB rat. 748 63

Induction of nitric oxide synthase and generation of nitric oxide in pancreatic islet beta-cells may mediate cytokine-induced dysfunction leading to insulin-dependent diabetes mellitus. Nitric oxide generation can be regulated by availability of arginine substrate which, in turn, may be affected by substrate utilization in competing pathways such as the arginase-catalysed formation of ornithine and urea. In this study we have investigated the activity of arginase in the rat insulinoma-derived cell line RINm5F and the effect on this of interleukin 1beta, the nitric oxide synthase reaction intermediate NG-hydroxy-l-arginine and the nitric oxide-generating compounds 3-morpholinosydnonimine and S-nitrosoglutathione. Cytosols from RINm5F cells treated with or without interleukin 1beta (0.1nM, 18h) were incubated (45min, 37 degrees C) with [U-14C]arginine. Radiolabelled products ([14C]citrulline from nitric oxide synthase, [14C]ornithine and [14C]urea from arginase) were separated by high-performance liquid chromatography or ion-exchange chromatography. Interleukin 1beta increased citrulline production (from 0.01+/-0.002 to 0.58+/-0.03 pmol/microg cell protein), indicating induction of nitric oxide synthase, and significantly decreased production of both ornithine (from 4.60+/-0.20 to 3.40+/-0.20 pmol/microg) and urea (0.93+/-0.05 to 0.69+/-0.04 pmol/microg) (P<0.001), indicating decreased activity of arginase. Arginase was significantly inhibited by NG-hydroxy-l-arginine (IC50=50 microM), S-nitrosoglutathione (500 microM: 69+/-7% of control) and 3-morpholinosydnonimine (1 mM: 57+/-7% of control) (P<0.05). We conclude that during cytokine-directed beta-cell assault nitric oxide synthase-catalysed production of NG-hydroxy-l-arginine and nitric oxide may inhibit arginase thereby increasing the availability of arginine for nitric oxide production.
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PMID:Interleukin 1beta-mediated inhibition of arginase in RINm5F cells. 924 84

This work was carried out to study the modulation of arginase expression in experimental diabetes. Here, we have demonstrated that liver arginase activity and mRNA levels increased significantly in diabetic condition. Insulin treatment reverses the increased activity and mRNA levels nearly to the control values. The reversal effects of vanadate are found to be similar to that of insulin and this observation further reiterates the insulin-like effects of vanadate. ELISA and slot blot assay observations are consistent with biochemical measurements of enzyme activity. These results show an increase in arginase activity and mRNA levels in diabetes and decrease in treated animals may be due to the transcriptional regulation of arginase gene.
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PMID:Modulation of mRNA levels of liver arginase by insulin and vanadate in experimental diabetes. 1054 72

This work was carried out to study the effects of vanadate on the expression of liver-type arginase in experimentally induced diabetes in the rat. The results showed that the activity and mRNA levels of arginase were increased significantly in the diabetic condition. Vanadate treatment reversed the increased activity and restored mRNA levels of arginase almost to the control values. The reversal effects of vanadate were found to be similar to those of insulin, and this further confirms the insulin-like effects of vanadate. ELISA and slot-blot assay observations were consistent with the biochemical measurements of enzyme activity. The increase in arginase activity and mRNA levels in diabetes and the decrease in insulin- and vanadate-treated animals may be due to the transcriptional regulation of arginase.
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PMID:Effects of vanadate on expression of liver arginase in experimental diabetic rats. 1079 4

Diabetes impairs wound healing and there are few therapeutic options to reverse it. Previous work has demonstrated the importance of nitric oxide for successful wound healing. In diabetes, NO synthesis is reduced in the wound milieu. The amino acid L-arginine is the only substrate for NO synthesis. We hypothesized that L-arginine supplementation would enhance wound healing by restoring NO synthesis. Thirty-six male Sprague-Dawley rats (body weight, 225 to 250 g) were separated in 4 groups: 20 rats were rendered diabetic 7 days prior to wounding by intraperitoneal streptozotocin (STZ) injection (70 mg/kg). Sixteen rats served as controls. Half of the animals of each group received 1 g/kg supplemental L-arginine administered by gavage twice daily. Control rats were gavaged with water. Treatment was started 3 days before wounding. All rats underwent a dorsal skin incision and subcutaneous implantation of polyvinyl alcohol (PVA) sponges. The rats were killed 10 days post wounding and wound breaking strength, hydroxyproline content of the sponges, nitrite/nitrate (NO(x)) concentration, arginase activity, and amino acid composition of the wound fluid and plasma were analyzed. Wound fluid NO(x) concentrations and wound breaking strength were significantly reduced in the diabetic group compared to the controls. L-Arginine treatment restored diabetic NO(x) levels toward normal values and significantly enhanced wound breaking strength. Wound fluid arginase activity and ornithine concentrations were significantly lower in the diabetic animals but unaffected by treatment. The data demonstrate that the impaired NO synthesis in the diabetic wound milieu can at least partially be reversed by arginine supplementation. In view of previous results on the importance of NO for wound healing, the data suggest that arginine supplementation restores impaired healing in this acute wound model by normalizing the NO pathway but without affecting arginase activity.
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PMID:L-Arginine supplementation enhances diabetic wound healing: involvement of the nitric oxide synthase and arginase pathways. 1237 Aug 45


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