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)

We examined the effect of scavengers of reactive oxygen metabolites on proteinuria in the passive Heymann nephritis model of membranous nephropathy. Passive Heymann nephritis was induced by a single intravenous injection of anti-Fx1A IgG in a dose of 10 mg/100 g body weight. Superoxide dismutase, a scavenger of superoxide or catalase which destroys hydrogen peroxide, did not affect the proteinuria. In contrast, dimethylthiourea (DMTU, 500 mg/kg followed by 125 mg/kg ip twice a day), a scavenger of hydroxyl radical, markedly reduced the proteinuria (day 5: anti-Fx1A 53 +/- 13, n = 18; anti-Fx1A + DMTU, 21 +/- 6 mg/24 h, n = 15, P less than 0.001). Experiments with 125I-labeled anti-Fx1A antibody demonstrated that DMTU did not affect the amount of antibody deposited in the kidney. Semiquantitative estimation of IgG and complement deposition in the kidney showed no differences between the DMTU-treated and control rats. A second hydroxyl radical scavenger, sodium benzoate (150 mg/kg ip twice a day), also resulted in marked reduction in proteinuria (day 5: anti-Fx1A 56 +/- 7, n = 9; anti-Fx1A + benzoate, 14 +/- 4 mg/24 h, n = 8, P less than 0.01). Because of the participation of iron in biological systems to generate hydroxyl radical, we also examined the effect of deferoxamine (DFO, 35 mg/day), an iron chelator, on the anti-Fx1A-induced proteinuria. There was a significant reduction in proteinuria in rats treated concurrently with DFO (day 5: anti-Fx1A 67 +/- 13, n = 15; anti-Fx1A + DFO, 29 +/- 4 mg/24 h, n = 15, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Evidence suggesting a role for hydroxyl radical in passive Heymann nephritis in rats. 283 37

The acute phase of glomerular injury in a model of antiglomerular basement membrane, antibody-induced glomerulonephritis (antiGBM-GN) in rabbits was shown to be neutrophil-dependent using nitrogen mustard depletion studies. Administration of desferrioxamine (DFX) prevented the development of proteinuria in this model of renal injury [24 hr protein excretion (mean +/- SEM): antiGBM-GN/DFX = 16.2 +/- 2.9 mg compared with antiGBM-GN control = 271.5 +/- 92.2 mg, P less than 0.01]. Antibody binding levels, glomerular filtration rates, circulating complement and neutrophil counts, glomerular C3 deposition, and neutrophil infiltration did not differ between DFX treated and antiGBM-GN groups. In vitro assay systems to assess oxygen radical production [superoxide anion (O2-) and hydroxyl radical (OH.)] by neutrophils activated via the interaction of antiGBM antibody, GBM and complement were established. In these assays, DFX inhibited OH. production by immunologically-stimulated neutrophils (ISN) [nM diphenol/hr/10(6) cells, mean +/- SEM, ISN/DFX = 8 +/- 2 compared with ISN = 191 +/- 22, P less than 0.01] while production of O2- was not affected [nM O2-/hr/10(6) cells, mean +/- SEM, ISN/DFX = 29.1 +/- 4.3 compared with ISN = 32.6 +/- 2.5, P greater than 0.05]. These studies demonstrate that the iron chelator desferrioxamine can prevent neutrophil-dependent immune renal injury by interfering with neutrophil function. Treatment with the hydroxyl radical scavenger dimethylthiourea also significantly attenuated renal injury in antiGBM-GN. Together, the in vivo and in vitro data strongly suggest that neutrophil-dependent immunological renal injury is mediated via hydroxyl radical production by activated neutrophils within glomeruli.
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PMID:Hydroxyl radical mediation of immune renal injury by desferrioxamine. 302 99

Reactive oxygen species, particularly hydrogen peroxide (H2O2), participate in neutrophil-mediated glomerulonephritis. However, the mechanism of H2O2 neptrotoxicity is unknown. Myeloperoxidase (MPO), a neutrophil cationic enzyme that localizes in glomeruli, can react with H2O2 and halides to form highly reactive products. We tested the hypothesis that the MPO-H2O2-halide system may induce glomerular injury by infusing MPO followed by H2O2 in a chloride-containing solution into the renal artery of rats. Controls received MPO or H2O2 alone. MPO-H2O2-perfused rats developed significant proteinuria, endothelial cell swelling, and epithelial cell foot process effacement, whereas control kidneys were normal. In the presence of free 125I, MPO-H2O2-perfused rats incorporated large amounts of 125I, localized to the glomerular basement membrane and mesangium by autoradiography, into glomeruli. Glomerular iodination was greatly decreased or absent in controls. The MPO-H2O2-halide system causes glomerular injury and may be important in neutrophil-mediated glomerulonephritis.
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PMID:New mechanism for glomerular injury. Myeloperoxidase-hydrogen peroxide-halide system. 303 23

Numerous trials have shown the efficacy of ACE-inhibitors in moderate and severe essential hypertension. Their use must be regarded as very promising. They lower peripheral vascular resistance without influencing cardiac index and heart rate. Additionally, they maintain serum potassium and do not effect plasma lipids or provoke diabetes mellitus or gout. In 20-30% of hypertensive patients ACE-inhibitors have to be combined with diuretics and/or calcium antagonists. The addition of beta-blockers is useful in patients with resting tachycardia. In mild hypertension the use of ACE-inhibitors as first-line drugs is indicated in patients with adverse reactions to beta-blockers or diuretics. In bilateral renovascular hypertension, ACE-inhibitors may induce a strong blood pressure fall; in bilateral stenosis they contribute to a deterioration of renal function with reversible renal insufficiency. In renoparenchymal hypertension, ACE-inhibitors may attenuate the progression of renal insufficiency; in addition, proteinuria is lowered. In systolic hypertension in the elderly, one must be aware of a marked first-dose hypotensive effect. ACE-inhibitors decrease exaggerated exercise-induced elevation of blood pressure and heart rate and therefore lower myocardial oxygen consumption. In patients with hypertension and diabetes mellitus, antihypertensive treatment should be initiated for blood pressure levels above 140/90 mmHg, to attenuate the progression of vascular damage in the kidney. In patients with severe left ventricular hypertrophy, ACE-inhibitors reduce left ventricular mass within three months by about 30%. In hypertension and coronary heart disease, recent studies report benefits of ACE-inhibitors on coronary circulation. Presently available ACE-inhibitors and those in preparation do not differ in pharmacodynamic, but in pharmacokinetic properties, concerning the beginning and duration of blood pressure lowering. A hypotensive first-dose effect can be observed in diuretic pretreated patients, in severe (malignant) and renovascular hypertension. ACE-inhibitors should not be used during pregnancy or in patients with autoimmune diseases or those undergoing treatment with immunosuppressive drugs, due to the side effects of neutropenia and proteinuria, which are more often seen under these conditions. Results from long-term studies on the influence of ACE-inhibitor treatment on cardiovascular risk in mild hypertension have not been available until now. In the decision to treat mild hypertension with ACE-inhibitors as first-line drug therapy, the costs of therapy in comparison to cheaper antihypertensives must be taken into account.
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PMID:[The value of angiotensin-converting enzyme inhibitors in the treatment of hypertension]. 306 60

Platelet-activating factor (PAF) is a lipid mediator of inflammation believed to play a role in glomerulonephritis by favoring immune complex formation and modulating the subsequent inflammatory reaction. Some evidence indicates that PAF may also be one of the mediators of proteinuria. Previous work suggested that PAF can increase glomerular permeability to proteins, activating platelets and inflammatory cells to release cationic proteins. In the present study, we addressed the possibility that PAF might directly increase glomerular permeability to proteins independently of platelets and inflammatory cells. We used a preparation of isolated rat kidney perfused with an artificial cell-free medium. After stabilization and two 10-minute control clearance periods, kidneys perfused in a closed circuit were exposed to PAF (2 nM or 10 nM final concentration) or 2-lyso-PAF (10 nM final concentration) or vehicle for 40 minutes. Glomerular filtration rate, measured as creatinine clearance, and renal vascular resistance did not significantly change when either PAF (2 nM or 10 nM) or 2-lyso-PAF, or vehicle were added to the perfusion fluid. Unlike vehicle or 2-lyso-PAF, addition of PAF at the final concentration of 2 and 10 nM to the perfusate produced a dose-dependent progressive increase in urinary protein excretion. PAF-induced proteinuria was prevented by L-652,731, a specific PAF receptor antagonist, suggesting that PAF's effect on glomerular permeability to proteins is likely to be related to its biologic activity. Several pharmacologic manipulations addressed to the potential mediators of PAF effect on glomerular permeability to proteins would exclude that the effect of PAF on isolated perfused kidney is mediated by cyclooxygenase or lipoxygenase products, or is the result of oxygen-free radical generation. The possibility that PAF enhances glomerular permeability to proteins by changing the glomerular barrier electrostatic properties was explored using polyethylene-imine. Electron microscopy examination revealed no difference in the distribution of electron-dense deposits along the glomerular basement membrane in kidneys exposed to 10 nM PAF or vehicle.
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PMID:Effect of platelet-activating factor and its specific receptor antagonist on glomerular permeability to proteins in isolated perfused rat kidney. 312 98

Two patients with severe obstructive sleep apnea syndrome and high-grade proteinuria (greater than 1 g/d [1000 mg/d]) were studied. Three remissions in proteinuria coincided with correction of obstructive sleep apnea syndrome and improvement of blood oxygen levels. These remissions could be dissociated from reductions both in dry body weight and in hematocrit levels. We propose that sleep apnea may cause a functional and reversible type of proteinuria.
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PMID:Reversible proteinuria in obstructive sleep apnea syndrome. 333 6

To assess the effects of acute exercise on renal prostaglandins E2 (PGE2) and F2 alpha (PGF2 alpha) synthesis, urine collections were obtained from six women before and after 30 min of treadmill exercise at approximately 80% of their maximal oxygen consumption. After receiving a placebo for 3 days, with acute exercise, there was a significant increase only in recovery urine PGE2 concentration. Due to a decline in urine volume, PGF2 excretion was unchanged and PGF2 alpha excretion was significantly decreased by exercise. Subjects repeated the tests after 3 d of indomethacin treatment (150 mg X d-1), a known renal prostaglandin (PG) inhibitor, and 3 d of sulindac (300 mg X d-1), a non-steroidal anti-inflammatory drug which may not inhibit renal PG synthesis. Pre-exercise urine PGE2 concentrations were decreased by indomethacin but not by sulindac, whereas, PGF2 alpha concentrations were decreased by both drugs. When compared to the control test, indomethacin and sulindac had different effects on pre-exercise urine/plasma osmolality ratios and free water clearances. Neither indomethacin nor sulindac influenced the decreases in free water clearances, which were observed during the placebo tests. Exercise proteinuria was significantly increased by indomethacin but not by sulindac. In conclusion, these data demonstrate that acute exercise may stimulate renal PGE2 synthesis. During exercise, renal PG synthesis attenuates protein excretion. There also appear to be differences between indomethacin and sulindac with regard to the effects on renal PG synthesis and kidney function.
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PMID:Renal prostaglandin E2 and F2 alpha synthesis during exercise: effects of indomethacin and sulindac. 353 27

The cellular processes responsible for the proteinuria induced by the aminonucleoside of puromycin (PA) remain inadequately defined. Hypoxanthine is both a metabolic breakdown product of PA as well as a substrate for xanthine oxidase, which catalyzes its enzymatic conversion to xanthine and uric acid, yielding the superoxide anion in the process. We examined whether oxygen free radical production contributes to the development of proteinuria in this model. Seven groups of male Sprague-Dawley rats were studied. Proteinuria was quantitated and histology examined 7 days after rats were treated with PA intravenously over 5 min. PA-treated animals received either saline, dimethyl sulfoxide, superoxide dismutase, or catalase over 30 min prior to and 30 min following PA administration. Another group received allopurinol over 4 hr prior to PA. The superoxide dismutase and allopurinol treatment groups had a significant suppression of urinary protein excretion compared to the PA control group. There were also less severe glomerular morphologic changes in the superoxide dismutase group vs. the PA controls, which demonstrated a pathologic pattern that included epithelial cell blebbing, segmental mesangial cell proliferation and matrix expansion, loss of glomerular capillary lumina, and occasional adhesions between the glomerular tuft and Bowman's capsule. The allopurinol group exhibited normal glomerular morphology on light microscopy, with the exception of occasional epithelial cell blebs. All groups showed spreading of the epithelial cell cytoplasm along the glomerular basement membrane with loss of foot processes, focal areas of lifting of the epithelial cell from the glomerular basement membrane, cytoplasmic vacuolization, and protein reabsorption droplets; however, allopurinol-treated animals demonstrated these changes to a lesser extent.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A role for oxygen free radicals in aminonucleoside nephrosis. 370 6

Phorbol myristate acetate (PMA) is known to be a potent activator of neutrophils and macrophages resulting in the generation of large amounts of oxygen-free radicals by these cells. When injected into the left renal artery of 250 to 300 g male Sprague-Dawley rats, PMA caused significant proteinuria compared to control rats which received normal saline (35.4 +/- 4 mg/24 hr in PMA treated vs. 14.1 +/- 0.9 mg/24 hr in saline control, P less than 0.02). The proteinuria was associated with evidence of glomerular injury. These PMA-induced alterations were not prevented by complement depletion but were prevented by prior depletion of neutrophils. The coinstillation of catalase prevented the development of the proteinuria (catalase + PMA 12.7 +/- 2.3 mg/24 hr vs. PMA alone 38.2 +/- 5.7 mg/24 hr, P less than 0.001) suggesting that H2O2 and/or its metabolites derived from neutrophils were important in the PMA-induced proteinuria. In contrast, superoxide dismutase (SOD) had no effect. We conclude that, following the intra-arterial injection of PMA, neutrophil-derived hydrogen peroxide and/or its metabolic products are capable of causing acute proteinuria in association with morphological alterations in glomeruli of rats.
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PMID:Role of oxygen radicals in phorbol myristate acetate-induced glomerular injury. 399 39

Previously we have demonstrated that systemic activation of the complement system after intravenous injection of cobra venom factor (CVF) results in acute lung injury as reflected by increases in the vascular permeability of the lung as well as by morphologic evidence of damage to lung vascular endothelial cells. In using the vascular permeability of the lung as the reference, the current studies show a quantitative correlation between lung injury and the appearance in plasma of lipid peroxidation products (conjugated dienes) as well as increased concentrations of lactic dehydrogenase (LDH) and one of its isoenzymes (LDH-4). After injection of CVF, extracts of lungs also showed elevated levels of conjugated dienes, whereas no elevations were found in extracts of liver, kidney, and spleen. There was no evidence in CVF-injected rats of renal or hepatic injury as reflected by the lack of development of proteinuria and the failure to detect increased serum levels of liver-related enzymes. Other peroxidation products identified in plasma of CVF-injected rats involved hydroperoxides and fluorescent compounds with features of Schiff bases. Not surprisingly, malondialdehyde was not found to be a reliable plasma indicator of lipid peroxidation associated with oxygen radical-mediated lung vascular injury. In using a model of oxygen radical-independent lung injury induced by oleic acid, although large amounts of LDH and LDH-4 were found in the plasma, no increases in plasma levels of conjugated dienes were detected. In CVF-injected animals treated with interventions protective against lung injury (neutrophil depletion, catalase, hydroxyl radical scavengers, or iron chelators), there were striking reductions in the plasma levels of conjugated dienes, hydroperoxides, and fluorochromic products. Morphometric analysis of lung sections revealed that the protective interventions did not interfere with the accumulation of neutrophils in lung interstitial capillaries after systemic activation of complement. In vitro studies with phorbol-stimulated neutrophils failed to demonstrate appearance of conjugated dienes, suggesting that the dienes appearing in plasma of CVF-injected animals are not the result of autotoxic changes in neutrophils. The data presented in this paper suggest that acute lung injury mediated by oxygen radicals derived from phagocytic cells can be monitored by the appearance in plasma of products of lipid peroxidation.
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PMID:Systemic complement activation, lung injury, and products of lipid peroxidation. 403 Oct 60


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