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)

Diabetes mellitus, a disease with a wide prevalence, has major cardiovascular effects, being a risk factor for the development of ischemic heart disease and congestive heart failure. The aim of this open, multicenter study was to assess the antiischemic efficacy and tolerability of trimetazidine, a metabolic agent acting at the myocardial mitochondrial level, in diabetic patients with stable effort angina treated previously with a single conventional antianginal drug. Fifty diabetic patients (mean age 58 years) with proven coronary artery disease, stable effort angina for at least 3 months, and positive, comparable results of two initial treadmill exercise tests separated by a 1-week interval were included in the study. They continued their conventional antianginal monotherapy with a long-acting nitrate, beta-blocker, or calcium channel blocker. After stabilization, 4-week therapy with trimetazidine, three times daily, 20 mg was initiated in combination with previous treatment. The results showed a significant improvement in exercise tolerance (440.2 vs. 383.2 s; P < 0.01), time to 1-mm ST-segment depression (358.3 vs. 301.6 s; P < 0.01), time to onset of anginal pain (400.0 vs. 238.3 s; P < 0.01), and total work (9.39 vs. 8.67 metabolic equivalents, P < 0.01). Maximal ST-segment depression was attenuated compared with baseline (1.82 vs. 1.91 mm). Other findings included a significant decrease in the mean frequency of anginal episodes (3.06 vs. 4.79 per week; P < 0.01) and in mean nitrate consumption (2.29 vs. 4.2 doses/week). These results suggest that trimetazidine may be effective and is well tolerated as combination therapy for diabetic coronary artery disease patients uncontrolled with a single hemodynamic agent.
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PMID:The antiischemic effects and tolerability of trimetazidine in coronary diabetic patients. A substudy from TRIMPOL-1. 1043 84

Experiments were designed to investigate the effects of chronic administration of an NO donor, (+/-)-(E)-ethyl-2-[(E)-ethylhydroxyimino]-5-nitro-3-hexeneamide (FK409), on the impairment of the acetylcholine-induced endothelium-dependent relaxations of the aorta, perfused mesenteric arterial bed and perfused kidney that seen in streptozotocin-induced diabetic rats. In aortic strips and in the perfused kidney, the decreased acetylcholine-induced relaxation seen in diabetes was restored to normal by chronic (daily for 4 weeks) administration of FK409 (20 mg/kg or 10 mg/kg, respectively). Acetylcholine increased the NOx (NO2- and NO3-) level in the perfusates from aortic strips, the perfused kidney and the perfused mesenteric arterial bed. These increases were significantly weaker for diabetic rats than for the controls. This effect of diabetes was ameliorated by chronic administration of FK409 (20 mg/kg) in aortic strips and perfused kidney, but not in the perfused mesenteric arterial bed. These results demonstrate that chronic administration of the novel NO releaser FK409 can improve diabetes-impaired endothelium-dependent vasodilatation in the rat aorta and perfused kidney.
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PMID:Effects of chronic treatment with the spontaneous nitric oxide releaser FK409 on vascular responses in established streptozotocin-induced diabetic rat. 1050 39

Production of free radicals from acetaldehyde oxidation by enzymes and cellular fractions is a well-known process. The toxic effects of acetaldehyde, however, are usually attributed to its reactions with biomolecules to produce adducts. Here, we demonstrate that hypothetical adducts produced from attack of acetaldehyde by two important biological oxidants, peroxynitrite and hydrogen peroxide, decompose to produce acetate, formate, and methyl radicals. Acetate, formate, nitrate, and nitrite were characterized and quantified by capillary electrophoresis. Radicals were detected and quantified by the EPR spectra produced in the presence of spin traps 3, 5-dibromo-4-nitrosobenzenesulfonic acid and 5,5-dimethyl-1-pyrroline N-oxide. Kinetic studies and product analysis were performed at different pHs. The results demonstrate that production of methyl radicals during oxidation of acetaldehyde by hydrogen peroxide was strictly dependent on the presence of iron(II) and occurred via two routes. One involved acetaldehyde attack by the hydroxyl radical to produce the acetyl radical that decomposes to methyl radical and carbon monoxide. The other route involved acetaldehyde attack by deprotonated hydrogen peroxide to produce a hypothetical intermediate that reductively cleaves via the action of present iron(II) to produce radicals. The latter mechanism predominates in the case of peroxynitrite, but radical formation does not require metal ions. Most of the hypothetical adduct produced from acetaldehyde and peroxynitrite (k = 680 M(-)(1) s(-)(1) at pH 7.4 and 37 degrees C) decays to nitrate and regenerates the aldehyde [Uppu, R. M., et al. (1997) Chem. Res. Toxicol. 10, 1331], but about 30% of it produces acetate, formate, and methyl radicals. Part of these oxidized products result from beta-scission and 1,2-shift reactions of the 1-hydroxyethoxyl radical which, together with nitrogen dioxide, freely diffuses from the adduct (20% yields). The results provide yet another example of the metal-independent free radical reactivity of peroxynitrite and may be relevant to the toxic effects associated with heavy drinking and diabetes.
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PMID:Oxidation of acetaldehyde by peroxynitrite and hydrogen Peroxide/Iron(II). Production Of acetate, formate, and methyl radicals. 1052 79

Changes in activity or expression of protein kinase C (PKC), reactive oxygen products, and nitric oxide (NO) may account for the alteration in cell behavior seen in diabetes. These changes have been proposed to be part of the pathophysiology of erectile dysfunction. We sought to ascertain if corpus cavernosal vascular smooth muscle cells (CCSMC) grown in a high glucose milieu exhibit changes in the activity and expression of PKC isoforms, NO, and reactive oxygen products and to find out if these changes are prevented by alpha-tocopherol. Rat CCSMC were grown in 5, 15, and 30 mM glucose concentrations for 3, 7, and 14 days. PKC isoform expression was assayed with isoform-specific antibodies. In CCSMCs grown in 30 mM glucose for 2-wk, PKC-beta(2)-isoform was upregulated (n = 4; P < 0.01), whereas the expression of alpha-, delta-, epsilon-, and beta(1)-isoforms was unchanged. NO as measured by nitrate-to-nitrite ratio was greatly diminished at 14 days in 30 mM (n = 4; P < 0.002) compared with 5 mM glucose. Reactive oxygen products were upregulated at 14 days when they were assayed by the fluorescent probe dichlorofluorescein diacetate bis(acetoxy-methyl) (DCFH-DA) (n = 5; P < 0.01). When these same cells were exposed to alpha-tocopherol for 14 days, there was a reduction of PKC-beta(2) (57.8%; P < 0.01; n = 4) and a reduction in reactive oxygen product formation (71.1%; P < 0.001; n = 4), along with an increase in nitrate-to-nitrite ratio (43.9%; P < 0.01, n = 4). These results suggest that there may be an interrelationship between PKC, NO, and reactive oxygen product formation in CCSMC exposed to a high glucose environment.
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PMID:Glucose-induced changes in protein kinase C and nitric oxide are prevented by vitamin E. 1064 49

Streptozotocin (STZ) is a widely used diabetogenic agent that damages pancreatic islet beta cells by activating immune mechanisms, when given in multiple low doses, and by alkylating DNA, when given at a single high dose. Actually, STZ contains a nitroso moiety. Incubation of rat islets with this compound has been found to generate nitrite; moreover, photoinduced NO production from STZ has been demonstrated. These reports have suggested that direct NO generation may be a mechanism for STZ toxicity in diabetogenesis. Several other studies have denied such a mechanism of action. This study has shown that (1) the multiple low-dose (MLDS) treatment does not stimulate NO production at the islet level; in fact, nitrite + nitrate levels and aconitase activity (also in the presence of an NO-synthase inhibitor, namely NAME) remain unmodified; RT-PCR analysis demonstrates that this treatment does not stimulate iNOS activity; (2) the high-dose (HDS) treatment does not stimulate NO production; in fact nitrite + nitrate levels remain unmodified and iNOS mRNA levels are not altered, although aconitase activity is significantly decreased. Moreover, we have confirmed that the MLDS treatment is able to decrease SOD activity by day 11 and that STZ, given in a single high dose, transiently increases superoxide dismutase (SOD) values (24 h from the administration), then dramatically lowers SOD levels. On the basis of our results, we conclude that STZ, "in vivo" is unable to generate NO, both as a MLDS or HDS treatment, thus excluding that NO exerts a role in streptozotocin-dependent diabetes mellitus.
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PMID:Multiple low-dose and single high-dose treatments with streptozotocin do not generate nitric oxide. 1067 19

We used streptozotocin (STZ) to induce the animal model of diabetes mellitus in rats. On the 7th and 14th days of induction, kidney disorder, the levels of NO3- in plasma and tissue homogenate in different periods were observed. The NO3- levels in relation to the application of L-arginine (L-Arg) were also noted. The results showed that the kidney weight/body weight ratio significantly increased in different periods (P < 0.05). On the 7th day profuse proteinuria appeared and it markedly increased on the 14th day: creatinine clearance rate (Ccr) significantly raised, too (P < 0.005). The NO3- levels in plasma and tissue homogenate were getting higher with time. The level of NO3- significantly increased after L-Arg was perfused. It indicated that kidney disorder was present at the early stage of diabetes, and the raised Ccr indirectly indicated the increase of glomerular filtration rate. These suggest that NO3- and L-Arg may be important mediums which have effects of hyperfiltration and hyperperfusion of glomerulus.
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PMID:[L-arginine and nitric oxide have effects on glomerulus hyperperfusion of early diabetic rats]. 1068 27

In recent years, several studies have addressed a possible relationship between nitrate exposure and childhood type 1 insulin-dependent diabetes mellitus. The present ecologic study describes a possible relation between the incidence of type 1 diabetes and nitrate levels in drinking water in The Netherlands, and evaluates whether the World Health Organization and the European Commission standard for nitrate in drinking water (50 mg/L) is adequate to prevent risk of this disease. During 1993-1995 in The Netherlands, 1,104 cases of type 1 diabetes were diagnosed in children 0-14 years of age. We were able to use 1,064 of these cases in a total of 2,829,020 children in this analysis. We classified mean nitrate levels in drinking water in 3,932 postal code areas in The Netherlands in 1991-1995 into two exposure categories. One category was based on equal numbers of children exposed to different nitrate levels (0.25-2.08, 2.10-6.42, and 6.44-41.19 mg/L nitrate); the other was based on cut-off values of 10 and 25 mg/L nitrate. We determined standardized incidence ratios (SIRs) for type 1 diabetes in subgroups of the 2,829,020 children with respect to both nitrate exposure categories, sex, and age and as compared in univariate analysis using the chi-square test for trend. We compared the incidence rate ratios (IRRs) by multivariate analysis in a Poisson regression model. We found an effect of increasing age of the children on incidence of type 1 diabetes, but we did not find an effect of sex or of nitrate concentration in drinking water using the two exposure categories. For nitrate levels > 25 mg/L, an increased SIR and an increased IRR of 1.46 were observed; however, this increase was not statistically significant, probably because of the small number of cases (15 of 1,064). We concluded that there is no convincing evidence that nitrate in drinking water at current exposure levels is a risk factor for childhood type 1 diabetes mellitus in The Netherlands, although a threshold value > 25 mg/L for the occurrence of this disease can not be excluded.
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PMID:Does the risk of childhood diabetes mellitus require revision of the guideline values for nitrate in drinking water? 1081 74

(1) The clinical file is bulky, including 14 double-blind, placebo-controlled trials conducted in normal conditions of use. (2) Sildenafil effectively treats the symptoms of erection disorders, whatever their origin (psychogenic or organic, especially spinal injuries). Efficacy seems slightly lower in case of diabetes or total prostatectomy. (3) Overall, sildenafil allows 80 to 90% of patients to have an erection adequate for sexual intercourse, but only one in two sexual acts on average were considered "satisfactory" by the clinical trial investigators. (4) Sildenafil does not affect sexual desire. It has not been studied in men without erection disorders. The results of ongoing trials in women are not yet known. (5) The adverse effects of sildenafil seem infrequent and generally mild. However, the risk of sudden arterial hypotension if the drug is combined with nitrate derivatives calls for careful safety monitoring. This combination is contraindicated. (6) In our opinion sildenafil should not be prescribed to anyone with cardiovascular risk factors or a history of heart problems.
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PMID:Sildenafil and erectile dysfunction: new preparation. Helpful. 1084 44

Diabetes is associated with endothelial dysfunction and increased risk of hypertension, cardiovascular disease, and renal complications. Earlier studies have revealed that hyperglycemia impairs nitric oxide (NO) production and diabetes causes endothelial dysfunction in humans and experimental animals. This study was designed to test the effects of altered concentrations of glucose, insulin, and glucagon, the principal variables in types I and II diabetes, on NO production and endothelial NO synthase (eNOS) expression in cultured human coronary endothelial cells. Cultured endothelial cells were incubated in the presence of glucose at either normal (5.6 mM) or high (25 mM) concentrations for 7 days. The rates of basal and bradykinin-stimulated NO production (nitrate + nitrite) and eNOS protein expression (Western blot) were then determined at the basal condition and in the presence of insulin (10(-8) and 10(-7) M), glucagon (10(-8) and 10(-7) M), or both. Incubation with a high-glucose concentration for 7 days significantly downregulated, whereas insulin significantly upregulated, basal and bradykinin-stimulated NO production and eNOS expression in cultured endothelial cells. The stimulatory action of insulin was mitigated by high-glucose concentration and abolished by cotreatment of cells with glucagon. Thus hyperglycemia, insulinopenia, and hyperglucagonemia, which frequently coexist in diabetes, can work in concert to suppress NO production by human coronary artery endothelial cells.
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PMID:Effects of simulated hyperglycemia, insulin, and glucagon on endothelial nitric oxide synthase expression. 1089 17

1. The aim of the present study was to investigate whether long-term oral administration of eicosapentaenoic acid increases nitric oxide (NO) production and affects cardiac sympathetic activity in rats with diabetes mellitus. 2. We measured changes in urinary excretion of NO3-, a stable NO metabolite, and cardiac noradrenaline (NA) concentrations in non-diabetic rats and streptozotocin-induced diabetic rats treated with either ethyl icosapentate (EPA-E; 100 mg/kg per day; n = 10), a purified ethyl esterification product of eicosapentaenoic acid, or vehicle (distilled water; n = 10) for 6 weeks. The effects of N(G)-nitro-L-arginine (L-NNA), a NO synthase inhibitor, on urinary NO3- excretion and cardiac NA concentrations were also investigated in diabetic rats treated with EPA-E. 3. Urinary NO3- excretion was higher at weeks 5 and 6 in diabetic rats treated with EPA-E than in diabetic rats treated with vehicle (week 5: 120+/-8 vs 51+/-11 micromol/g per day, respectively (P<0.01); week 6: 279+/-83 vs 73+/-9 micromol/g per day, respectively (P<0.01)). Cardiac NA concentrations were higher in diabetic rats than in non-diabetic rats and were decreased in the left atrium and both ventricles in diabetic rats treated with EPA-E compared with control. Systemic administration of L-NNA abolished the increase in urinary excretion of NO3- and the decrease in cardiac NA concentrations in diabetic rats treated with EPA-E. 4. Long-term oral administration of EPA-E may stimulate NO production and increased NO is likely to play a role in inhibiting enhanced cardiac sympathetic activity in diabetic rats.
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PMID:Eicosapentaenoic acid stimulates nitric oxide production and decreases cardiac noradrenaline in diabetic rats. 1090 92


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