Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033687 (proteinuria)
 24,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lecithin:cholesterol acyltransferase (LCAT) deficiency is a genetic disorder associated with low levels of serum HDL cholesterol. The proband of the Finnish LCAT-deficient family had corneal opacities, proteinuria, anemia with stomatocytosis, low serum HDL cholesterol (0.27 mmol/L), and low LCAT activity. Sequence analysis of his LCAT gene revealed compound heterozygosity for two different mutations: a C insertion in exon 1 between nucleotides 932 and 937 and a C-to-T point mutation in exon 6 at position 4976. The C insertion in exon 1 is predicted to result in premature termination and a truncated polypeptide containing only 16 amino acids. The C-to-T point mutation in exon 6 substitutes cysteine for arginine at residue 399. The functional significance of the Arg399-->Cys mutation was examined by expressing the mutated and wild-type LCAT cDNAs in COS cells. COS cells transfected with mutated and wild-type cDNAs showed comparable levels of mature LCAT mRNA. However, LCAT activity in the cell media of COS cells transfected with the mutant LCAT cDNA was significantly lower than that of COS cells transfected with the wild-type cDNA (1.4% versus 12.0% cholesterol esterified, respectively). A polymerase chain reaction-based duplex assay, in which both mutations can be detected simultaneously, was used for preliminary screening of Finnish subjects with serum HDL levels below 0.9 mmol/L; two additional individuals heterozygous for the Arg399-->Cys mutation were identified.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Two different allelic mutations in a Finnish family with lecithin:cholesterol acyltransferase deficiency. 774 57

We have previously shown beneficial effects of dietary protein restriction on transforming growth factor beta (TGF-beta) expression and glomerular matrix accumulation in experimental glomerulonephritis. We hypothesized that these effects result from restriction of dietary L-arginine intake. Arginine is a precursor for three pathways, the products of which are involved in tissue injury and repair: nitric oxide, an effector molecule in inflammatory and immunological tissue injury; polyamines, which are required for DNA synthesis and cell growth; and proline, which is required for collagen production. Rats were fed six isocaloric diets differing in L-arginine and/or total protein content, starting immediately after induction of glomerulonephritis by injection of an antibody reactive to glomerular mesangial cells. Mesangial cell lysis and monocyte/macrophage infiltration did not differ with diet. However, restriction of dietary L-arginine intake, even when total protein intake was normal, resulted in decreased proteinuria, decreased expression of TGF-beta 1 mRNA and TGF-beta 1 protein, and decreased production and deposition of matrix components. L-Arginine, but not D-arginine, supplementation to low protein diets reversed these effects. These results implicate arginine as a key component in the beneficial effects of low protein diet.
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PMID:L-arginine may mediate the therapeutic effects of low protein diets. 775 41

Endogenous nitric oxide (EDRF) plays an important role in the regulation of systemic and renal blood pressure by an alteration of vascular tone. To assess the effect of L-arginine (160 mumol/min i.v. for 3 hours), the precursor of EDRF, on blood pressure, protein-excretion and renal function (GFR = glomerular filtration rate, RPF = renal plasma flow) we performed a prospective, double blind, placebo controlled study. 18 patients with chronic glomerulonephritis (51.3 +/- 11.5 years), renal insufficiency (GFR < 65 ml/min) and hypertension were investigated for changes in GFR and RPF by continuous inulin- and PAH-clearances and for changes in permselectivity by determination of protein-excretion. L-arginine infusion results in a reduction of proteinuria (p < 0.05, t-test). There is no significant effect on renal hemodynamics and mean arterial pressure (MAP). Comparing the excretion of the endogenous proteins, only albuminuria is decreased significantly (p < 0.01), whereas IgG-excretion is reduced slightly (p < 0.05). This can be considered as an indicator of a special influence on the mesangial cells or the basement membrane of the glomerulum itself by EDRF. In conclusion L-arginine reduces protein-excretion without significant alterations in renal hemodynamics and so might prevent a decline in renal failure.
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PMID:Does L-arginine alter proteinuria and renal hemodynamics in patients with chronic glomerulonephritis and hypertension? 778 Dec 5

The fawn-hooded rat constitutes a spontaneous model for chronic renal failure with early systemic and glomerular hypertension, proteinuria (UpV) and high susceptibility to development of focal and segmental glomerular sclerosis (FGS). It has been argued that uninephrectomy (UNX) accelerates the development of glomerular injury by aggravation of glomerular hypertension and by an independent effect to promote glomerular enlargement. The present study was performed to further delineate the importance of these parameters for the development of FGS. At the age of eight weeks male rats were UNX and randomly assigned to either control (CON), enalapril (ENA) or Nw-nitro L-arginine methyl ester (NAME) treatment. In all groups glomerular hemodynamic studies were performed four weeks post-UNX. Systemic blood pressure and UpV were monitored for 4 to 12 weeks post-UNX. Kidneys were then prepared for morphologic study. ENA treatment achieved control of both systemic and glomerular hypertension, maintenance of glomerular hyperfiltration and hyperperfusion, increased ultrafiltration coefficient(Kf), and long-term protection against UpV and FGS. NAME rats showed aggravation of both systemic and glomerular hypertension, decreased renal perfusion and filtration with reduced Kf, and high filtration fraction. The incidence of FGS in NAME and CON groups was similar at 8 and 12 weeks post-UNX, respectively. Glomerular enlargement was present in CON and ENA rats, but did not correlate with injury, while glomerular tuft size was lowest in NAME rats, which displayed prominent glomerular injury. Systemic blood pressure correlated strongly with glomerular capillary pressure. We conclude that systemic and glomerular hypertension govern the development of UpV and FGS.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Modulation of glomerular hypertension defines susceptibility to progressive glomerular injury. 796 51

The present study was performed to test the hypothesis that excretion of nitric oxide metabolites, nitrate and nitrite, are decreased with progressive aging in rats and that a decrease in nitric oxide precursor, L-arginine, also decreases with aging. Urinary nitrate/nitrite excretory rates and serum L-arginine levels were measured in male Sprague Dawley rats, ranging in ages from 3 to 25 months. Proteinuria increased dramatically with aging. Conversely, urinary nitrate/nitrite excretion decreased by 50% and 80% in rats, aged 12 months and 17 months, respectively. There was no further decrease in urinary nitrate/nitrite excretion in very old rats, aged 23-24 months. Glomerular filtration rate (GFR) was also measured in some of the rats, aged 3-5 mos and 17 mos. GFR was not different between old and young rats, suggesting that a decrease in GFR could not account for the decrease in urinary nitrate/nitrite excretion in the old rats. However, serum L-arginine levels were decreased with aging, by 30% and 50% in rats, aged 13-15 months and 24-25 months, respectively, when compared with young rats. These data confirm our hypothesis and suggest that nitric oxide (NO) production may decrease with aging and that one mechanism by which nitric oxide production could be decreased with age is a lack of the endogenous substrate, L-arginine. Because NO has been implicated to be involved in many physiological processes, age-related decreases in NO production could have far-reaching adverse effects in the aging individual.
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PMID:Changes in nitric oxide precursor, L-arginine, and metabolites, nitrate and nitrite, with aging. 799 Jun 49

Chronic nitric oxide inhibition exacerbates hypertension and nephrosclerosis in spontaneously hypertensive rats (SHRs). In this study, we determined whether angiotensin-converting enzyme (ACE) inhibition could prevent or reverse the systemic, renal, and glomerular hemodynamic alterations and the pathological changes of nephrosclerosis. Four groups of 20-week-old SHRs were studied: group 1, untreated controls; group 2, treated with N omega-nitro-L-arginine methyl ester (L-NAME, 50 mg/L for 3 weeks); group 3, L-NAME cotreated with quinapril (3 mg.kg-1.d-1 for 3 weeks); and group 4, L-NAME for 3 weeks followed by quinapril for 3 weeks (same doses). The results of this study demonstrated that both cotreatment (group 3) and posttreatment (group 4) with quinapril reduced mean arterial pressure (186 +/- 9 and 192 +/- 9 mm Hg, respectively, compared with group 2 SHRs, 221 +/- 5 mm Hg) and total peripheral resistance index associated with significant reductions in afferent and efferent arteriolar resistances; nephrosclerosis pathological scores; and urinary protein excretion (all at least P < .01). ACE inhibition also significantly increased stroke index, single-nephron glomerular filtration rate, and ultrafiltration coefficient compared with the L-NAME SHRs. Most notable were the findings that cotreatment with quinapril completely prevented the renal glomerular hemodynamic alterations with reduced glomerular capillary hydrostatic pressure and efferent arteriolar resistance compared with both the untreated and the L-NAME-treated SHRs (all at least P < .01). Posttreatment with quinapril also reversed the glomerular injury (subcapsular, -83%; juxtamedullary, -56%) and arteriolar (-87%) injury scores obtained from renal biopsy specimens (P < .005 and P < .0001, respectively). These changes were associated with decreased periarteriolar fibronectin and increased afferent arteriolar alpha-smooth muscle actin deposition (immunohistochemistry). These data, therefore, demonstrate that ACE inhibition not only prevents but also reverses L-NAME-exacerbated severe nephrosclerosis in SHRs, as indicated by improved systemic, renal, and glomerular hemodynamic changes, proteinuria, and histological alterations.
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PMID:ACE inhibition prevents and reverses L-NAME-exacerbated nephrosclerosis in spontaneously hypertensive rats. 856 38

Decreased response to vasopressor agents characterizes pregnancy. Endothelium-derived relaxing factors and vasodilating prostaglandins play an important role in the vascular tone during pregnancy. Since inhibition of nitric oxide (NO) biosynthesis induced by NO2-arginine enriched diet produced hypertension we measured in vivo cardiovascular responses to PGF2 alpha, L-arginine (L-arg) and cicletanine (Cic, IPSEN, France) which enhances PGI2 production. From day 13 to day 20 of gestation 4 groups of female Wistar rats were fed NO2-arg (31 mg/kg/d), NO2-arg+Cic (10 mg/kg/d), Cic enriched or control diet (C). Mean arterial pressure (MAP) was measured via a carotid catheter in anesthetized rats. Injection of PGF2 alpha (50 micrograms/kg) in jugular vein significantly increased MAP in the NO2-arg group versus, NO2-arg+Cic, Cic and C group (+23.5 +/- 3.3 vs +15.7 +/- 2.2, +15.8 +/- 2.2 and +17 +/- 1.85 mmHg; p < 0.01). Injection of L-arg (100 mg/kg) or Cic (1 mg/kg) 5 min before PGF2 alpha produced no modification in MAP in C and Cic group. Likewise in NO2-arg group injection of L-arg or Cic produced a diminished pressor response to PGF2 alpha (+23.5 +/- 3.3 vs -17.5 +/- 1.7 mmHg; p < 0.05 and +15.2 +/- 2.4 mmHg; p < 0.01 respectively). In NO2-arg+Cic group, only injection of Cic induced a diminished pressor response to PGF2 alpha which is more important without L-arg (+15.7 +/- 2.2 vs +9.1 +/- 1.3 mmHg; p < 0.001) or with L-arg (+13.6 +/- 1.5 vs +9.1 +/- 1.3 mmHg; p < 0.01). Cicletanine also significantly diminished the proteinuria in the NO2-arg+Cic group versus NO2-arg group (13.9 +/- 4.36 vs 63.4 +/- 21.6 mmHg; p < 0.01). IN CONCLUSION, chronic NO synthesis inhibition enhanced blood pressure and pressor responses to PGF2 alpha during pregnancy in rats. Chronic administration of cicletanine in Wistar pregnant rats decreases the response to vasopressor agents like PGF2 alpha. Moreover acute and chronic administration of cicletanine blunted the pressor effect, which was lower than in normal gestation.
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PMID:[Chronic and acute effect of cycletanine in NO-dependent hypertensive pregnant rats]. 857 78

Nitric oxide (NO) synthesis is induced in glomeruli in glomerulonephritis; its role in the pathogenesis of glomerular injury is unknown. Interpretation of its role using the currently available analogues of L-arginine as in vivo inhibitors of NO is complicated by their lack of specificity for inducible NO synthase (iNOS). As NO synthesis by iNOS depends on extracellular L-arginine, we have here examined effects of L-arginine depletion on glomerular NO synthesis and the course of accelerated nephrotoxic nephritis (NTN). Arginase, which converts L-arginine to urea and L-ornithine, was used to achieve L-arginine depletion. A single dose of i.v. arginase produced complete depletion of plasma arginine for four hours. Two forms of NTN were induced in preimmunised rats by nephrotoxic globulin: (1) the systemic form of the model by intravenous nephrotoxic globulin; or (2) the unilateral form of model by left kidney perfusion with nephrotoxic globulin, which avoids the complications of systemic administration of nephrotoxic globulin. Arginase reduced plasma arginine levels and the synthesis of nitrite (the stable end-product of NO) by NTN glomeruli (95% inhibition). Proteinuria was exacerbated. There was no effect on early (24 hr) leukocyte infiltration. In the systemic form of the model arginine depletion by i.v. arginase increased glomerular thrombosis at 24 hours, and the severity of histological changes at four days, accompanied by systemic hypertension. In the unilateral form of the model, where i.v. arginase did not induce hypertension, there was no increase in thrombosis or histological severity of nephritis. These results show that arginine depletion, which inhibits glomerular NO synthesis in NTN, leads to increased proteinuria. Where injury is severe, or accompanied by systemic hypertension, the disease is further exacerbated by glomerular thrombosis. These results suggest that NO has an important role in limiting acute glomerular injury.
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PMID:L-arginine depletion inhibits glomerular nitric oxide synthesis and exacerbates rat nephrotoxic nephritis. 869 29

A point mutation in exon 6 of the alpha-galactosidase A gene (alpha-GAL A) was found in a Japanese hemizygous male without typical manifestations of Fabry disease other than renal involvement. This 45-year-old man developed moderate proteinuria and was diagnosed with Fabry disease on the basis of renal histologic findings and prominent decreases in alpha-GAL A activity in his plasma, urine, leukocytes, and skin fibroblasts. Determination of the cDNA sequence of his alpha-GAL A gene revealed substitution of a G to A in codon 301, resulting in a glutamine rather than an arginine residue. Our case is unique in that this patient only demonstrated renal manifestations while all other reported patients with atypical Fabry disease, including a case with the identical point mutation, present with a cardiomyopathy. Direct DNA sequencing of exon 6 and measurement of alpha-GAL A activity among the patient's family confirmed that the mutation was transmitted from his mother.
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PMID:Point mutation in the alpha-galactosidase A gene of atypical Fabry disease with only nephropathy. 873 59

The kidneys play an important role in the development of cardiovascular risk factors. It is well known that heavy proteinuria can induce hyperlipidemia, the uric acid is elevated in some renal deficiencies and that hypertension develops in most end stage renal diseases. In prehypertensive states, specially in subjects with a family history of hypertension, some hemodynamic changes take place, characterized by an increase in renal vasoconstriction with a reduction in renal plasma flow and an elevation of sodium reabsorption. The mechanisms for these alterations are not well understood, but an increase in intracytosolic calcium in vascular smooth muscle cells, a reduction in vasodilatory substances such as nitric oxide and an increased sympathetic nervous activity have been proposed. In normotensive subjects with two hypertensive parents a reduction in sodium diet, an increase in protein intake or in arginine diet could prevent established essential hypertension from developing. In borderline hypertension an early therapy with low doses of calcium antagonists, ACE inhibition or diuretics could be indicated.
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PMID:Can the kidney prevent cardiovascular diseases? 874 38


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