Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0406810 (NAME)
 13,345 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dietary protein independently modulates albuminuria (U(Alb)V) and albumin synthesis (AlbSyn) in nephrotic rats. While some amino acids are without effect on renal hemodynamics, arginine (Arg) augments renal blood flow and glomerular filtration rate, increases AlbSyn in tissue culture and isolated perfused livers, and could be one specific amino acid causing both decreased glomerular permselectivity and increased AlbSyn. Nephrotic rats were fed 10% casein (LP); 30% casein (HP); 30% casein with the inhibitor of nitric oxide (NO) synthesis N omega-nitro-L-arginine methyl ester (HP + L-NAME); 10% casein supplemented with Arg and amino acids that are Arg precursors of or are derived from Arg (proline, glutamate, and aspartate) in an amount in the increment between 10 and 30% casein (ArgAA); ArgAA supplemented with NH4 acetate to provide a diet isonitrogenous to 30% casein (ArgAA + NH4); or 10% casein plus an incomplete mixture of amino acids (Inc) containing the increment in histidine, phenylalanine, tryptophan, tyrosine, lysine, glycine, alanine, serine, threonine, cysteine, and methionine provided when the diet was changed from 10 to 30% casein. U(Alb)V increased significantly in HP and by a significantly greater amount in HP + L-NAME, but did not change in LP, ArgAA, or ArgAA + NH4. U(Alb)V tended to increase in Inc, was significantly greater than in LP or in ArgAA + NH4, but less than in HP. AlbSyn ([3H]phenylalanine incorporation) was no different in Inc than in HP, and was significantly greater than in either ArgAA + NH4 or LP. Increased AlbSyn results from increased ingestion of one or more of amino acids in Inc, but not from Arg or its precursors or products or from total dietary nitrogen.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Arginine augments neither albuminuria nor albumin synthesis caused by high-protein diets in nephrosis. 144 79

We evaluated nitric oxide release in several models of intestinal inflammation through luminal nitrite concentrations. In anesthetized rabbits, piglets, and guinea pigs, luminal lavages were collected from loops of normal or injured small intestine. Lavages were analyzed spectrophotometrically for nitrite (Griess reagent) and protein. Myeloperoxidase (MPO) content of intestinal segments was used as an index of granulocyte infiltration and intestinal inflammation. Acute ileal inflammation was induced by luminal acetic acid + casein in rabbits and luminal deoxycholate in neonatal piglets and adult rabbits. Chronic ileitis was induced in guinea pigs by intraluminal trinitrobenzenesulfonic acid. In each model nitrite levels in ileal lavages were significantly greater than control loops/animals. Increased luminal protein and intestinal MPO activity paralleled the changes in nitrite levels. To determine whether nitric oxide production influenced mucosal repair, segments of ileum were perfused with the L-arginine antagonist NG-nitro-L-arginine methyl ester (L-NAME, 10 mg/ml) after acute acetic acid + casein exposure. L-NAME administration reversed the decline in epithelial permeability characteristic of epithelial restitution, causing an increase in epithelial permeability which was readily reversible. These results suggest that nitrite production is a useful index of gut injury and that nitric oxide may contribute to the functional repair of the epithelial barrier under acute conditions.
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PMID:Nitric oxide release in response to gut injury. 838 36

Nitric oxide (NO) plays a major role in gut mucosal protection and motility. Having demonstrated the protective effects of intravenous L-arginine (L-arg) and the NO donor, sodium nitroprusside (SNP), in an in-vivo premature piglet intraluminal model of necrotizing enterocolitis (NEC) that incorporates both mucosal damage and intestinal dysmotility, we measured the effects on NO synthase (NOS) isoenzyme activities during i.v. manipulation of the nitrergic system in the NEC-injured gut. In newborn premature Yorkshire piglets, NEC was induced in four groups by intraluminal injection of acidified casein solution in closed test loops of bowel separated by normal saline-injected control loops. Group 1 (n = 4) underwent no further treatment. Group 2 (n = 4) received concomitant continuous i.v. L-arg, a NO substrate. Group 3 (n = 6) received concomitant continuous i.v. SNP, a NO donor. Group 4 (n = 5) received concomitant continuous i.v. N-omega-nitro-L-arginine-methyl-ester (L-NAME), a non-selective NO inhibitor. Control and test gut specimens were harvested after 3 h. NO synthase activity in frozen gut segments was assessed using the (14)C-L-arg to (14)C-L-citrulline conversion assay. Total NOS (TNOS), constitutive NOS (cNOS), and inducible NOS (iNOS) activities were compared. The mean and standard error were calculated for each specimen. Group means were used to compare test and control gut enzyme activities in the different treatment groups. One-way analysis of variance and the Bonferroni post test were used to compare differences among groups. A P value of less than 0.05 was considered significant. In the L-NAME group, cNOS activity was lower than in the untreated NEC group. The SNP group had higher iNOS and TNOS activities than the L-arg group; cNOS was also higher in test and control loops in the SNP versus both L-arg and L-NAME groups. However, in L-arg control loops, cNOS activity was greater than in the L-NAME group. SNP and L-arg treatment of NEC did not significantly modify NOS isoenzyme activities. Thus, in this premature piglet 3-h model of NEC, i.v. L-NAME significantly decreases cNOS activity and correlates with our previously published histopathologic findings confirming the protective role of cNOS-derived NO in NEC-injured gut mucosa. In order to further elucidate the mechanisms involved in the mucosal protection afforded by i.v. L-arg and SNP in this NEC model, studies of a longer duration have been undertaken.
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PMID:Nitric oxide synthase isoenzyme activities in a premature piglet model of necrotizing enterocolitis: effects of nitrergic manipulation. 1247 79

Tested was the hypothesis that enhanced nitric oxide (NO) production that is stimulated by increased renal endothelin activity mediates decreased distal nephron HCO(3) secretion that is induced by dietary protein. Munich-Wistar rats that ate minimum electrolyte diets with 50% casein-provided protein (HiPro) compared with controls that ate 20% protein for 3 wk had higher urine excretion of endothelin-1 (80 +/- 15.7 versus 29 +/- 3.9 fmol/kg body wt per d; P < 0.02) and of the NO metabolites NO(2)/NO(3) (21.2 +/- 1.9 versus 14.9 +/- 0.8 mumol/kg body wt per d; P < 0.03). Bosentan, an endothelin A/B receptor antagonist, reduced HiPro rats' urine excretion of net acid (5859 +/- 654 versus 8017 +/- 1103 micromol/d; P < 0.03, paired t test) and NO(2)/NO(3) (18.1 +/- 1.1 versus 22.9 +/- 2.0 micromol/kg body wt per d; P < 0.05, paired t test). N-nitro-l-arginine methyl ester (L-NAME), an NO synthase inhibitor, also decreased urine net acid excretion (6621 +/- 717 versus 8449 +/- 1086 micromol/d; P < 0.05, paired t test) but was not additive to bosentan. L-NAME increased in situ late distal nephron HCO(3) delivery in HiPro rats (18.8 +/- 1.7 versus 9.6 +/- 1.4 pmol/mm per min; P < 0.001) that was mediated by increased distal nephron HCO(3) secretion (-7.2 +/- 0.7 versus -3.5 +/- 0.4 pmol/mm per min; P < 0.001) without changes in distal nephron transtubule HCO(3) permeability or H(+) secretion. Bosentan decreased H(+) secretion and increased HCO(3) secretion in the distal nephron of HiPro rats, but L-NAME had no additive effect on either component. The data support that dietary protein augments distal nephron acidification through decreased HCO(3) secretion that is mediated through endothelin-stimulated NO.
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PMID:Endothelin-induced increased nitric oxide mediates augmented distal nephron acidification as a result of dietary protein. 1639 62

The inducible nitric oxide synthase (iNOS) is abundantly expressed by smooth muscle cells and macrophages in atherosclerotic lesions. Apolipoprotein E-deficient (apoE(-/-)) mice develop early and advanced atherosclerotic lesions. The role of iNOS in both early and advanced atherosclerotic formation was determined in apoE(-/-) mice. Mice were fed chow or a Western diet containing 42% fat, 0.15% cholesterol, and 19.5% casein. At 12 weeks of age on chow diet, iNOS(-/-)/apoE(-/-) mice developed comparable sizes of early atherosclerotic lesions in the aortic root as did iNOS(+/+)/apoE(-/-) mice (30,993+/-4746 vs. 26,648+/-6815 microm(2)/section; P=0.608). After being fed the Western diet for 12 weeks, iNOS(-/-)/apoE(-/-) mice developed significantly smaller advanced lesions than iNOS(+/+)/apoE(-/-) mice (458,734+/-14,942 vs. 519,570+/-22,098 microm(2)/section; P=0.029). This reduction in lesion formation could not be explained by differences in plasma lipid levels. To examine whether iNOS contributed to LDL oxidation, smooth muscle cells were isolated from the aorta, activated with TNF-alpha, and then incubated with native LDL in the absence or presence of N-Omega-nitro-L-arginine methyl ester (L-NAME), a specific NOS inhibitor. L-NAME significantly inhibited LDL oxidation by smooth muscle cells from iNOS(+/+)/apoE(-/-) mice (P=0.048), but it had no effect on LDL oxidation by cells from iNOS(-/-)/apoE(-/-) mice. iNOS(-/-)/apoE(-/-) mice had a significantly lower plasma lipoperoxide level on the Western diet (2.74+/-0.23 vs. 3.89+/-0.41 microM MDA; P=0.021) but not on chow diet (1.02+/-0.07 vs. 1.51+/-0.29 microM MDA; P=0.11). Thus, the absence of iNOS-mediated LDL oxidation may contribute to the reduction in advanced lesion formation of iNOS(-/-)/apoE(-/-) mice.
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PMID:Deficiency of inducible NO synthase reduces advanced but not early atherosclerosis in apolipoprotein E-deficient mice. 1651 41