TRANSLATIONAL PHYSIOLOGYProinflammatory effects of oxidative stress in chronic - 《American Journal of Physiology》美国生理学杂志干细胞之家



免疫细胞治疗专区	欢迎关注干细胞微信公众号

12 3 4 5 6 7 8 9 10 ... 24 下一页

返回列表

查看: 404834\|回复: 235	go TRANSLATIONAL PHYSIOLOGYProinflammatory effects of oxidative stress in chronic [复制链接]

轻羽

新手上路

Rank: 1

积分: 0
威望: 0
包包: 0

楼主

发表于 2009-4-21 13:34 |只看该作者 |倒序浏览 |打印

作者：RajivAgarwal作者单位：(With the Technical Assistance of Shawn D. Chase)Indiana University School of Medicine and Richard L. Roudebush Veterans Affairs Medical Center, Indianapolis, Indiana 46202
   # y+ f+ t! t! G$ M





         * T, |9 P; R% w) r

                  3 b, `, |  d' U- L0 }

      6 J+ h, Y& [( e) @6 O

      【摘要】
   Oxidative stress playsan important role in causing progressive chronic kidney disease (CKD).We examined the influence of add-on ANG II receptor blockadeadministered as losartan (50 mg/day for 1 mo) on oxidative stress andproinflammatory state of the kidney in patients with CKD. All subjectswere taking an angiotensin-converting enzyme inhibitor plus otherantihypertensive agents. Oxidative stress to lipids and proteins wasmeasured by an HPLC assay for malondialdehyde (MDA) and carbonylconcentration, respectively. Urinary inflammation was measured bymonocyte chemotactic protein-1 (MCP-1) excretion rate. The etiology ofCKD was type 2 diabetes mellitus in 12 and glomerulonephritis in 4 patients. There was no change in proteinuria or 24-h ambulatory bloodpressure (BP) with add-on ANG II receptor blockade with losartantherapy. Before losartan therapy, urinary protein and albumin oxidationwere 99 and 71% higher, respectively, compared with in plasma( P There was a 35% reduction in urinaryoxidized albumin with add-on losartan therapy ( P = 0.036). Urinary and plasma MDA were elevated compared with age-matchedcontrols. Urinary MDA was significantly reduced from 4.75 ± 3.23 to 3.39 ± 2.17 µmol/g creatinine with add-on losartan therapy.However, plasma MDA or oxidized proteins did not change in response toadditional ANG II blockade. A good correlation was seen between thechange in urinary oxidized albumin and MCP-1 levels ( r = 0.61, P = 0.012). These data demonstrate thatoxidative damage to urinary protein and lipids can be reduced with additional ANG II receptor blockade, independently of reductions in proteinuria or BP. Urinary measurements of markers of oxidative damage to lipids and proteins appear to be more sensitive than plasmameasurements in patients with CKD. The significant association of thechange in urinary MCP-1 with a reduction in oxidative stress supportsthe role of the redox state in the kidney with renal fibrosis andprogressive kidney damage.
      【关键词】 carbonyl stress malondialdehyde proteinurea hypertension diabetes mellitus
   INTRODUCTION
! m+ M( G" X# t# o
ELEVATED BLOOD PRESSURE and severe proteinuria are important predictors ofprogressive renal injury ( 13 ). How proteinuria results intubulointerstitial injury, the single strongest determinant of thelong-term loss of glomerular filtration rate leading to end-stage renaldisease, is incompletely understood ( 14 ). The presentparadigm of proteinuria as a mediator of tubulointerstitial damage isbased on the observations that albumin can stimulate the production ofproinflammatory cytokines in proximal tubular cells via activation ofthe redox-sensitive gene nuclear factor- B ( 26, 27 ).Furthermore, chemokine expression in the kidney is modulated by theredox state, which in turn is modulated by angiotensin II. It is notknown whether oxidative stress and the proinflammatory state in thekidney can be favorably influenced without a reduction in bloodpressure or improvement in proteinuria. Such a demonstration can be ofpractical importance, because the present therapies of chronic kidneydisease (CKD) address the question of blood pressure and reduction inproteinuria but not the direct treatment of renal inflammation.

We have previously reported that add-on angiotensin II receptorantagonism with losartan, on a background of chronicangiotensin-converting enzyme (ACE) inhibition, did not reduceproteinuria or blood pressure ( 1 ) but caused a 38%reduction in urinary excretion of the fibrogenic cytokine transforminggrowth factor-. ( 3 ) In this group of patients, who hadno improvement in proteinuria or blood pressure, we found a uniqueopportunity to examine the role of specific angiotensin II type 1 receptor antagonism on oxidative stress and the proinflammatory effectsof this oxidative stress that are precursors of renal fibrosis. Wehypothesized that add-on losartan therapy will reduce oxidative lipidand protein damage in proteinuric patients with CKD and result inreduced urinary production of proinflammatory cytokines.
/ ?+ D7 F# }0 j1 [/ D5 E
METHODS

The protocol design and main results of the study have beenreported in detail previously ( 1 ). Briefly, patientsbetween the ages of 18 and 80 yr with proteinuria of 1 g/day,hypertension (defined as mean arterial pressure 97 mmHg), serumpotassium of 3 mo were eligible for the study. Patients who had previouslyreceived angiotensin receptor blockers or with estimated creatinineclearance of normotensive volunteers with no history of kidney diseaseor diabetes served as the control group for plasma and urinarymalodialdehyde (MDA) levels and estimation of plasma protein carbonylation.- i9 q1 T9 _- _! v2 x

Protocol. The study was a two-period, crossover, randomized controlled trial andhas been reported in detail elsewhere ( 1 ). Patients received a sequence of losartan (50 mg/day × 4 wk, 2-wk washout) and placebo × 4 wk, or placebo × 4 wk, 2-wk washout, andlosartan (50 mg/day × 4 wk). Lisinopril (40 mg/day) along withother antihypertensive therapy was continued throughout the trial.Urine was collected (24 h) for protein, sodium, urea, and creatinineand urinary carbonylated protein, MDA, and monocyte chemotacticprotein-1 (MCP-1) measurement. Because the standard therapy forpatients with proteinuria and renal failure includes ACE inhibitors, wedid not remove them from the regimen of any patient enrolled in thestudy. The study was approved by the Institutional ReviewBoard, and all patients gave informed written consent.
8 ?$ c% E5 J9 v5 e
Serum chemistries, complete blood counts, urine protein, electrolytes,and urea and creatinine were measured by our hospital laboratory usingroutine methods. Specifically, creatinine was measured on a Hitachi 911 analyzer (Boehringer Mannheim) using the alkaline picrate method, andurinary protein was measured using a turbidometric method, withbenzethonium chloride read at 550 nm (Roche Diagnostics, Indianapolis, IN).7 b% _- ?; \: Q( v) W$ j# o

Ambulatory blood pressure monitoring was performed with SpaceLabs 90207 monitors and glomerular filtration rate (GFR) measurements withcontinuous infusion of iothalamate as previously reported ( 1 ).

Plasma and urinary MDA assay. MDA, a lipid hydroperoxide, is formed by -scission of peroxidizedpolyunsaturated fatty acids and is commonly measured by derivatizationwith thiobarbituric acid (TBA) to yield a red compound ( 4 ). A rapid and sensitive fluorometric HPLC method wasdeveloped for the measurement of MDA in plasma and urine as a biomarker of oxidative damage to lipids ( 2 ). Briefly, the mobilephase consisted of a 40:60 ratio (vol/vol) of methanol to 50 mMpotassium monobasic phosphate at pH 6.8, pumped at a rate of 1.0 ml/min on a Hewlett-Packard Hypersil-ODS (5 µm, 100 × 4.6 mm) placed in a column warmer set to 37°C. Samples of serum and urine were treated with the antioxidant butylated hydroxytoluene and heat derivatized at 100°C for 1 h with thiobarbituric acid at an acid pH. Samples were extracted with n -butanol, and 10 µl ofthe extract were injected at 1-min intervals using an autosampler. AHewlett-Packard model 1046A programmable fluorescence detector was setat an excitation of 515 nm and emission of 553 nm. Retention time was1.87 min; however, the absence of interfering peaks allowed analysis to be carried out in increments of 1 min/sample. Within-day variability inestimation was between 8.6 and 10.3%. Between-day variability was3.6-7.9%. Recovery was between 88 and 101%.
: R% r1 v+ T6 N3 K& ?) O. s
Total plasma protein carbonyl measurement. The carbonyl groups, due to oxidative damage to proteins, can bedetected by derivatizing with dinitrophenyl hydrazine (DNP), separatingthe derivatizing agent from the proteins, and measuring the absorbanceat 360 nm. Although the derivatizing agent can be removed with multiplewashes of the protein pellet after derivatization, this entails loss ofprotein during the procedure. Therefore, we developed an HPLC methodfor measuring carbonylated proteins using a size-exclusion column toseparate the derivatized carbonyl groups from the derivatizing agentand monitoring the separation with a diode array detector. Briefly, themobile phase consisted of 200 mmol/l sodium monophosphate, pH 6.5, containing 1% SDS pumped at a rate of 1.0 ml/min on an AlltechMacrosphere GPC (7 µm, 250 × 4.6 mm, Alltech Associates,Deerfield, IL) placed in a column warmer set to 37°C. Samples ofplasma were split into two parts, one derivatized with 20 mmol/l DNP in10% trifluoroacetic acid (TFA) and the other acting as a controltreated with 10% TFA. Samples were injected using a HP1100 autosamplerin a volume of 25 µl of the derivatized and underivatized samples at8-min intervals. The Hewlett-Packard model 1100 diode array detector was programmed to retain signals every 2 nm over the 190- to 550-nm spectrum, and data were recorded using HPLC Chemstation software (Agilent Technologies, Palo Alto, CA). The retention time of protein was 3 min as confirmed by a maximum absorbance of the spectra at 190 nm; the derivatizing agent had a retention time of 7 min. The maximumabsorbance of DNP was noted at 360 nm. The area under the curve of the360-nm peak was integrated in the underivatized sample and subtractedfrom the derivatized sample. A molar extinction coefficient of 22,000 absorbance units/mol was used to determine the concentration ofcarbonyl in the sample. Data are expressed as nanomoles carbonyl permilligram protein.

Estimation of carbonylation in plasma and urinary protein byWestern blotting. Oxidation of plasma and urinary proteins was measured by analysis ofWestern blots according to the method of Shacter. Total protein wasdetermined using the Vitros Dry Slide system (Ortho-Clinical Diagnostics, Rochester, NY) in the clinical chemistry laboratory of thehospital. Plasma was diluted 1:25 (vol/vol) with PBS, one aliquot ofthe diluted sample was derivatized, and another was prepared as anunderivatized control using an OxyBlot protein oxidation detection kit(Intergen, Purchase, NY). Urine samples were similarly derivatized withDNP or control reagent except that samples were not diluted beforehand.Derivatized and underivatized plasma or urine samples were loaded onelectrophoresis gels in volumes calculated to give 5 µgprotein/sample and electrophoresed according to the method of Laemmlion 4-20% gradient SDS-PAGE gels (Bio-Rad, Hercules, CA) for 60 min at 200 V. After being electroblotted to 0.2-µm nitrocellulose for60 volt hours, the membrane was blocked with subsequent immunoblottingusing OxyBlot kit methods and reagents. Bands were visualized withchemiluminescent chemicals and captured on film at two exposure times(30 s and 1 min). Blots were scanned on a Hewlett-Packard ScanJet 5200C scanner (Hewlett-Packard, Palo Alto, CA) and analyzed for band areausing Un-Scan-It Gel software (Silk Scientific, Orem, UT).  b; A3 _* O2 O  p

Samples for individual patients before and after losartan therapy,including derivatized and underivatized control, were analyzed on asingle Western blot (Fig. 1 ). Thisensured that the response to losartan therapy was comparedunder the same analytic conditions. For each plasma or urine sample,carbonyl density was determined from the 30-s exposure, which producedclearly visible bands. Density of individual albumin bands and totalprotein in each sample lane were determined using a section of the samesize from each scanned blot. The analysis box included 26 lanes foreach analysis. The uniform window size and analysis box ensured that data were being analyzed consistently from band to band and from blotto blot. Additionally, any density values present in underivatized controls were subtracted from density of the DNP-treated sample toincrease the validity of comparison among patients.$ A% l4 _; L7 M' l% A; s! i
( j% p+ e/ a0 n1 [4 M0 x
Fig. 1. Western blots of oxidized proteins in urine( A ) and plasma ( B ). Each sample was run afterderivatization with dinitrophenyl hydrazine before (Pre) and after(Post) angiotensin II receptor blockade administered for 1 mo.Underivatized controls are negative for dinitrophenyl hydrazineantibody as expected. Pt1, Pt2, and Pt3: patient 1, patient 2, and patient 3, respectively.Background chemiluminescence was subtracted from the parent blot toobtain the true carbonylated fraction of protein.

Urinary MCP-1 assay. MCP-1 was assayed in urine using a sandwich ELISA (Quantikine kit forhuman MCP-1 immunoassay; R&D Systems, Minneapolis, MN). Correctionswere made for concentration, and values were expressed as nanogramsMCP-1 per gram creatinine. A standard curve was generated using afour-parameter logistic curve fit. The correlation coefficient 0.99, and the lowest detectable limit was 0.7 pg/ml in1:2 diluted urine. The intra-assay coefficient of variation was2.5 ± 3.0%, and the interassay coefficient of variation was 5.6 ± 4.2%.+ a! a; C7 W. ~8 q$ ~; q: X, o
; ^( h& E$ }7 A( V6 e4 U
Statistical analysis. The normality assumption was tested with the Kolmogorov-Smirnovstatistic. Urinary MCP-1 and protein excretion were not normally distributed and were log transformed to satisfy the normality assumption. These log-transformed data were used for subsequent analysis. Data were then analyzed by paired t -test beforeand after losartan therapy. Results are reported as means ± SD.All tests were two sided at an level of 0.05. All statisticalanalysis was carried out using standard procedures on Statistica forWindows, release 5.5 (StatSoft, Tulsa, OK, USA) ( 21 ).% A( P$ _+ G  A2 p  F- C7 R

RESULTS
2 y' T0 W2 h8 z
Sixteen patients (10 African Americans, 6 Caucasians; 14 men),with an average age of 53 ± 9 yr and body mass index of 38 ± 5.7 kg/m 2, completed the trial. The etiology of CKD wastype 2 diabetes mellitus in 12 patients and glomerulonephritis in theremaining 4. Seated blood pressure at baseline was 156 ± 18/88 ± 12 mmHg, requiring 3.13 ± 1.2 antihypertensivedrugs; creatinine was 2.0 ± 0.8 mg/dl; and proteinuriawas 3.6 ± 0.71 g · gcreatinine 1 · 24 h 1.; V) p! Y7 i$ U1 d( m
! {+ p2 M, T* {8 c3 a
There was no change in blood pressure or proteinuria in response toadd-on losartan therapy, as reported earlier ( 1 ). There was an improvement in GFR noted from 63 ± 9 to 68 ± 11 ml/min ( P was 99% higher than that seen in plasma( P = 0.008). Urinary albumin oxidation was 71% higherthan plasma albumin ( P = 0.045). Oxidized urinary orplasma albumin accounted for the major fraction of total proteinoxidation (Fig. 2, A and B ). Although proteinuria wasnot reduced, losartan significantly reduced oxidative damage to urinaryalbumin from 102,057 ± 87,149 to 66,110 ± 44,668 densitometric units/µg protein, a reduction of 35% (Fig. 2 A ). This effect was particularly pronounced in thosepatients who had a high level of oxidized albumin in the urine atbaseline. After treatment with losartan, urinary albumin was not moreoxidized compared with plasma albumin ( P = 0.45), buttotal urinary protein remained 69% more oxidized after losartantherapy ( P = 0.029). There was a trend towardimprovement in total urinary protein oxidation that did not reachstatistical significance, and plasma albumin and protein oxidationremained unchanged (Fig. 2 B ).
: N7 C9 o6 ]% L# c5 G( I. [8 F' o
Fig. 2. A : changes in urinary oxidized albumin and total protein[densitometric units (DU)/µg protein loaded on gel]. Urinaryoxidized albumin improved from mean of 102,057 to 66,110 DU/µgprotein ( P = 0.036), whereas urinary oxidized totalprotein remained unchanged. B : unchanged plasma oxidizedalbumin and total protein.2 j7 q0 K  I8 U) k; |+ @
( R3 V+ p4 u9 K8 |8 d4 d
Samples of urinary and plasma MDA from 10 normotensive volunteers, aged53 ± 14 yr, were 1.94 ± 0.79 µmol/g creatinine and 0.69 ± 0.13 µmol/l, respectively. In comparison, urinary andplasma MDA were elevated in the CKD patients. Urinary MDA wassignificantly reduced from 4.75 ± 3.23 to 3.39 ± 2.17 µmol/g creatinine with add-on losartan therapy (Fig. 3 ). However, neither plasma MDA (Fig. 3 )nor plasma oxidized proteins (Fig. 2 B ) changed in response to additional angiotensin II blockade. Using direct measurement ofprotein carbonylation in plasma, we found carbonyl concentration to beunchanged (61.3 ± 18.9 vs. 60.1 ± 19.1 µmol/l). Whenadjusted for plasma protein concentration, carbonyl concentration wasunchanged (0.84 ± 0.31 vs. 0.85 ± 0.44 nmol/mg), confirmingwhat was observed by Western blot analysis. The geometric urinary MCP-1fell, albeit statistically insignificantly, from 646 ± 3.2 to501 ± 3.0 pg/mg creatinine. Normal controls had a urinary MCP-1level of 203 ± 1.4 pg/mg creatinine. Finally, a good correlationwas seen between the change in urinary oxidized albumin and urinaryMCP-1 levels (Fig. 4 ).3 s7 K+ {+ V8 ~( |& {& a
5 a- R" p# D. i- b1 ?6 K% }
Fig. 3. Changes in plasma ( A ) and urinary ( B )malondialdehyde (MDA), a maker of lipid peroxidation. Although meanplasma MDA levels were elevated (1.10 ± 0.88 µmol/l) comparedwithin healthy controls (0.69 ± 13 µmol/l), there was noimprovement with therapy (0.81 ± 0.39 µmol/l posttherapy).However, angiotensin II receptor blockade caused significantimprovement in urinary MDA levels, from 4.75 ± 3.23 to 3.39 ± 2.17 µmol/g creatinine.
2 u' a, z$ R8 `* F0 C
Fig. 4. Reduction in urinary monocyte chemotactic protein-1 (MCP-1)correlated with reduction in urinary oxidized albumin with angiotensinII receptor blockade ( r = 0.61, P = 0.012).% e  i3 i# \  A  v( ^" ^
) X$ w/ ]- w% B5 w& f
DISCUSSION& q. j( ~: Y. ?% A9 ~' O

The major findings of our study are that patients with CKD withproteinuria have a greater concentration of biomarkers of oxidativestress in the urine compared with in plasma. Among proteins, albumin isthe major target of this oxidative damage. This oxidative stress can bereduced with angiotensin II receptor blockade independently of bloodpressure reduction or reduction in proteinuria. This improvement inreduced oxidative stress is correlated with improvement in urinary inflammation.$ ~+ p- x9 t# ^
7 e/ }* }! Z2 ^8 q
Increased plasma MDA in patients with CKD compared with healthycontrols suggests increased systemic oxidative stress. Although theincrease in vascular superoxide production via NADH/NADPH oxidase viaangiotensin II may be responsible for increased systemic oxidativestress ( 18 ), angiotensin II may play a larger role in thekidney due to its effects on superoxide anion production by themesangial cells and tubular cells ( 8, 11 ). Animal modelsof increased oxidative stress induced by diets deficient in vitamin Eand selenium show increased generation of reactive oxygen species,glomerular and tubular hypertrophy, and subsequent injury( 17 ). Thus the kidney may be particularly susceptible tooxidative stress. Our data demonstrating greater urinary protein carbonylation compared with plasma are therefore consistent with theabove observations made in cell cultures and animals.
- K" f3 W# _4 m4 k& j8 ?" w8 ^
The urinary environment is a prooxidant one, with measured amounts ofhydrogen peroxide attaining micromolar quantities in rats and humans( 16, 23 ). Plasma and the urinary excretion rates of MDA, abiomarker of lipid peroxidation, were elevated in patients with CKDcompared with normal controls. These data are consistent withobservations in animals with reduced renal mass who show increasedtubular oxygen consumption accompanied by increased MDA per tubule andincreased urinary and plasma levels of MDA ( 15 ). The fallin MDA excretion rate with additional angiotensin II antagonism,despite no change in plasma levels, suggests that the renal generationof MDA, but not the systemic production of MDA, was reduced. The knownprooxidant effects of angiotensin II on the kidney lend biologicalplausibility to these observations ( 8, 11 ). Thatstimulation of lipid peroxide production involved protein kinase C( 7 ), an enzyme whose activity is reduced byAT 1 receptor antagonism, may partly explain these results( 5 ). Although we did not find a correlation between thefall in urinary MDA excretion and reduction in urinary MCP-1, oxidizedlipids can increase chemokine expression in monocytes ( 22 )and mesangial cells ( 12 ). Therefore, a fall in urinary MDAexcretion may be a marker of reduced renal inflammation.
& `' B' y7 r! m% N
Angiotensin II blockade improved biomarkers of oxidative stress in theurine but not in plasma. In a model of chronic renal failure, in which 5 6 nephrectomized rats are treated with the ACE inhibitorenalapril, direct measurements of antioxidant enzymes in the kidneysuch as superoxide dismutase and glutathione peroxidase are increased( 24 ). The recruitment of antioxidant defenses, broughtabout by abrogation of actions of angiotensin II, may account for animprovement in the oxidative state in the kidney in preference to theplasma oxidative state.

Although there are a variety of cytokines that can be measured in theurine, we elected to measure MCP-1 for several reasons. MCP-1 has beenpreviously measured in the urine of patients with a variety ofglomerular diseases and was found to be biologically active and notcorrelated with plasma levels ( 19 ). Urinary excretion ofMCP-1 correlates with the extent of renal inflammation( 25 ) as well as MCP-1 gene expression in the tubules,parietal epithelial cells, and infiltrating monocytes ( 6 ).Therefore, we reasoned that urinary MCP-1 would serve as an importantmeasure of the inflammatory state in the kidney and its reduction wouldbe biologically plausible based on the animal experiments. Our datashow a good correlation between reduction in oxidative stress in urineand the reduction in renal inflammation, as measured by MCP-1. These data can be reconciled with the observation that reactive oxygen species generation is involved in MCP-1 gene transcription in responseto tissue injury, probably via NADPH-oxidase ( 20 ). Furthermore, in animal models of inflammatory kidney disease, administration of AT 1 receptor antagonists( 28 ) or the genetic absence of the AT 1a receptor ( 20 ) abrogates the early expression of MCP-1 inthe glomerulus and the infiltration of monocyte/macrophages.
( [* Z. F7 S  _" n0 e, @" R/ k
There are several limitations of our study. First, we did not studywhether ACE inhibitors alone can lower urinary oxidative damage inpatients with CKD and proteinuria. Although we show the effects ofangiotensin II receptor blockade to be independent of blood pressureand proteinuria, a study of the converse was not performed. In otherwords, it is not known whether blood pressure reduction orantiproteinuria therapies will result in a similar reduction in renaloxidative stress. Finally, a much larger trial would need to beconducted to show whether this strategy would translate into protectionfrom end-stage renal disease and death.2 ^, K  i, F5 ~# x( P! q; s9 A2 \

In this randomized controlled trial of additional angiotensin IIblockade, we have demonstrated that protein in the urine undergoesoxidative damage (urinary albumin was 71% more oxidized compared withplasma albumin). Thus in proteinuric patients urinary albumin can serveas a decoy of oxidative injury as it passes from the glomerulus intothe urine. Although such oxidative damage to plasma proteins inpatients with CKD has previously been reported ( 9, 10 ), webelieve that this is the first demonstration of oxidative damage tourinary proteins in humans. Furthermore, our data demonstrate thatoxidative damage to urinary protein and lipids can be reduced withadditional angiotensin II blockade. This is particularly notablebecause the reduction of oxidant stress occurred independently of areduction in proteinuria or blood pressure, the key mediators ofprogressive renal damage. Furthermore, there was no change in themarkers of protein or lipid damage in the plasma of these patients.Thus the data are consistent with the hypothesis that the urinarymeasurements of markers of oxidative damage, both carbonyls and lipidhydroperoxides, are more sensitive than plasma measurements in patientswith CKD. These observations are further strengthened through thesignificant association of the change in urinary MCP-1 with that inoxidized albumin, which supports experimental data in animalsdemonstrating the important role of the redox state in the kidney withrenal fibrosis and progressive kidney damage.

ACKNOWLEDGEMENTS- p( k( g0 F- O1 m- l+ V

We gratefully acknowledge the assistance of Dr. David P. Sundinwith Western blotting." F% }8 Y1 L4 K4 w. `- h
      【参考文献】; M- z5 a! j8 S2 _( p
1. Agarwal, R. Role of add-on angiotensin receptor blockade with maximized ACE inhibition. Kidney Int 59:2282-2289,2001  .; c4 L, E8 D5 r' y4 P% a9 ~" \( Y

6 I2 F' I2 |8 Q) B( ?

2. Agarwal, R,andChase SD. Rapid, fluorimetric-liquid chromatographic determination of malondialdehyde in biological samples. J Chromatogr B Analyt Technol Biomed Life Sci 775:121-126,2002  .
2 A& `7 o7 H9 \! \8 U+ Q8 v! P

7 h- P' W8 b' t9 g  a) E1 [
3. Agarwal, R,Siva S,Dunn SR,andSharma K. Add-on angiotensin II receptor blockade lowers urinary transforming growth factor-beta levels. Am J Kidney Dis 39:486-492,2002  .5 _- w; ~0 z9 O" [, j
) S& N5 E- `: v3 W1 R
- m9 \! V6 ]4 g% w

4. Esterbauer, H,andCheeseman KH. Determination of aldehydic lipid peroxidation products: malonaldehyde and 4-hydroxynonenal. Methods Enzymol 186:407-421,1990 .

1 F5 Q! T! j* f% o  c$ C

5. Goodfriend, TL,Elliott ME,andCatt KJ. Angiotensin receptors and their antagonists. N Engl J Med 334:1649-1654,1996 .
$ |7 w4 P$ J1 J1 l
" \  j9 A, h' e$ I7 X8 _# S

6. Grandaliano, G,Gesualdo L,Ranieri E,Monno R,Montinaro V,Marra F,andSchena FP. Monocyte chemotactic peptide-1 expression in acute and chronic human nephritides: a pathogenetic role in interstitial monocytes recruitment. J Am Soc Nephrol 7:906-913,1996 .
; }$ ~# ~% J$ f4 N! a
) |1 ~3 I! L" ?. I# c8 Y

7. Ha, H,andEndou H. Lipid peroxidation in isolated rat nephron segments. Am J Physiol Renal Fluid Electrolyte Physiol 263:F201-F207,1992 .7 I- j4 H. a  o7 ]; y- J& o7 ?
8 J- s/ [8 r# t0 V2 w
8 P" L, g+ A8 c8 b- m& J

8. Hannken, T,Schroeder R,Stahl RA,andWolf G. Angiotensin II-mediated expression of p27Kip1 and induction of cellular hypertrophy in renal tubular cells depend on the generation of oxygen radicals. Kidney Int 54:1923-1933,1998  .

! ^4 n7 A- X, B  e( ]
. j+ v1 t6 y- V, Z- s& R8 {
9. Himmelfarb, J,andMcMonagle E. Albumin is the major plasma protein target of oxidant stress in uremia. Kidney Int 60:358-363,2001  .! f3 T. P2 R; C" E. P
; ]; z: M( Z( j' p* [8 M7 n& o

10. Himmelfarb, J,McMonagle E,andMcMenamin E. Plasma protein thiol oxidation and carbonyl formation in chronic renal failure. Kidney Int 58:2571-2578,2000  .8 L% F, R. L$ o

11. Jaimes, EA,Galceran JM,andRaij L. Angiotensin II induces superoxide anion production by mesangial cells. Kidney Int 54:775-784,1998  .! O' u+ S4 f, @$ T8 [
& q& Y, E$ }$ D* l, j6 u

5 r0 \/ p* W! }+ m
12. Kamanna, VS,Pai R,Roh DD,andKirschenbaum MA. Oxidative modification of low-density lipoprotein enhances the murine mesangial cell cytokines associated with monocyte migration, differentiation, and proliferation. Lab Invest 74:1067-1079,1996  .
/ a- j- E8 x! ?6 ]9 D. M
0 ~5 Z) N- A, o( l7 p2 M9 p

13. Klahr, S,Levey AS,Beck GJ,Caggiula AW,Hunsicker L,Kusek JW,andStriker G. The effects of dietary protein restriction and blood-pressure control on the progression of chronic renal disease. Modification of Diet in Renal Disease Study Group. N Engl J Med 330:877-884,1994 .2 n. r' ]/ Q& k  |

14. Nath, KA. Tubulointerstitial changes as a major determinant in the progression of renal damage. Am J Kidney Dis 20:1-17,1992  .
! \# E, r3 o+ ]
( E) I* M# |' P- `/ o% g* N2 {
! x# ^# @$ H# |* c- |# L
15. Nath, KA,Croatt AJ,andHostetter TH. Oxygen consumption and oxidant stress in surviving nephrons. Am J Physiol Renal Fluid Electrolyte Physiol 258:F1354-F1362,1990 .: J+ h6 ?5 \$ q5 |2 I) Y

16. Nath, KA,Ngo EO,Hebbel RP,Croatt AJ,Zhou B,andNutter LM. -Ketoacids scavenge H 2 O 2 in vitro and in vivo and reduce menadione-induced DNA injury and cytotoxicity. Am J Physiol Cell Physiol 268:C227-C236,1995 .

, b; C0 x: E4 N5 L1 c
17. Nath, KA,andSalahudeen AK. Induction of renal growth and injury in the intact rat kidney by dietary deficiency of antioxidants. J Clin Invest 86:1179-1192,1990  .
2 f4 S7 }( @1 S% Y% Z. M$ Z

& I; s! X5 ?. g  s$ W$ P3 {9 w
18. Rajagopalan, S,Kurz S,Munzel T,Tarpey M,Freeman BA,Griendling KK,andHarrison DG. Angiotensin II-mediated hypertension in the rat increases vascular superoxide production via membrane NADH/NADPH oxidase activation. Contribution to alterations of vasomotor tone. J Clin Invest 97:1916-1923,1996  .+ V7 R6 H; f- B) e

1 ?  C3 ]- |2 u  u$ m& P
19. Rovin, BH,Doe N,andTan LC. Monocyte chemoattractant protein-1 levels in patients with glomerular disease. Am J Kidney Dis 27:640-646,1996  .
2 p- F% z' `# e. @

" i% `2 G3 f3 W% S
20. Satriano, JA,Shuldiner M,Hora K,Xing Y,Shan Z,andSchlondorff D. Oxygen radicals as second messengers for expression of the monocyte chemoattractant protein, JE/MCP-1, and the monocyte colony-stimulating factor, CSF-1, in response to tumor necrosis factor-alpha and immunoglobulin G. Evidence for involvement of reduced nicotinamide adenine dinucleotide phosphate (NADPH)-dependent oxidase. J Clin Invest 92:1564-1571,1993  .
# _: F: @. b! v# r2 Z% R
1 ]- q& W" ^6 x8 \
" y; m5 d/ e6 h* s$ Q& x; ?
21. StatSoft, Inc.. Statistica User Manual (5.5). Tulsa, OK: StatSoft, Inc., 2000.
' s% f1 k; a4 w  e* `! `

1 E) S3 N8 h' ]' R2 K% w
22. Terkeltaub, R,Banka CL,Solan J,Santoro D,Brand K,andCurtiss LK. Oxidized LDL induces monocytic cell expression of interleukin-8, a chemokine with T-lymphocyte chemotactic activity. Arterioscler Thromb 14:47-53,1994 .& ?- n) x" w' L# s2 \' M

: |( \3 ]+ f7 R2 C

23. Varma, SD,andDevamanoharan PS. Excretion of hydrogen peroxide in human urine. Free Radic Res Commun 8:73-78,1990  .3 k, W$ Q  K" k' f
- X$ |- _6 k4 N0 c
4 X2 S( ~8 i7 z0 I3 z

24. Verbeelen, DL,De Craemer D,Peeters P,Vanden Houte K,andVan den Branden C. Enalapril increases antioxidant enzyme activity in renal cortical tissue of five-sixth nephrectomized rats. Nephron 80:214-219,1998  .& J$ O5 |; `$ p) L% X
  Q1 O" y6 ]$ }

25. Wada, T,Yokoyama H,Su SB,Mukaida N,Iwano M,Dohi K,Takahashi Y,Sasaki T,Furuichi K,Segawa C,Hisada Y,Ohta S,Takasawa K,Kobayashi K,andMatsushima K. Monitoring urinary levels of monocyte chemotactic and activating factor reflects disease activity of lupus nephritis. Kidney Int 49:761-767,1996  .6 o4 c- Y7 W, ]& i1 h

26. Wang, Y,Chen J,Chen L,Tay YC,Rangan GK,andHarris DC. Induction of monocyte chemoattractant protein-1 in proximal tubule cells by urinary protein. J Am Soc Nephrol 8:1537-1545,1997 .

: [1 v" e* A" B: a, |
- A( ?" ~; ~. P% D7 _
27. Wang, Y,Rangan GK,Tay YC,Wang Y,andHarris DC. Induction of monocyte chemoattractant protein-1 by albumin is mediated by nuclear factor kappaB in proximal tubule cells. J Am Soc Nephrol 10:1204-1213,1999 .

" e! Y/ J! v2 {
" M# i. _) {! \9 L4 w
28. Wolf, G,Schneider A,Helmchen U,andStahl RA. AT 1 -receptor antagonists abolish glomerular MCP-1 expression in a model of mesangial proliferative glomerulonephritis. Exp Nephrol 6:112-120,1998  .

收藏0 分享0 顶0 踩0