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1.
Clin Nephrol ; 72(6): 482-7, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19954726

RESUMO

Two patients were contaminated by hepatitis during kidney transplantation from unrelated living donors, performed abroad in 2006. One patient died from fulminant hepatitis C (the first case of virus genotype 6a diagnosed in Israel) 2 months after transplantation and the other developed acute hepatitis B with YMDD to YVDD mutation necessitating life-long antiviral therapy. The dilemma of antiviral therapy in transplant recipients is discussed in this paper. Patients awaiting kidney transplantation by far outnumber the kidneys available for cadaver transplantation. International trade with living non-related kidneys has therefore become common. Comorbid conditions, although significant, are often ignored. After transplantation, the first patient presented with a picture of fulminant hepatitis C; immunosuppressive medication was tapered rapidly. This patient subsequently died from hepatic failure. The patient with active hepatitis B with YVDD mutation is receiving ongoing treatment by lamivudine and adefovir.


Assuntos
DNA Viral/análise , Hepacivirus/genética , Hepatite C/virologia , Falência Renal Crônica/cirurgia , Transplante de Rim/efeitos adversos , Doença Aguda , Adulto , Evolução Fatal , Seguimentos , Genótipo , Hepatite C/transmissão , Humanos , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase
2.
Clin Nephrol ; 61(3): 222-4, 2004 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15077875

RESUMO

A patient with end-stage kidney disease is described, who lost his renal allograft in the early post-transplant period due to allograft renal vein thrombosis. Prior to transplantation, he had been treated by hemodialysis and lost several vascular accesses because of thrombosis. A search for potential thrombophilic factors disclosed a unique combination of increased clotting factor levels, i.e. FVIII, FIX, FXI and homocysteine. More common hereditary and acquired hypercoagulability factors have been excluded in this patient. While clotting factor deficiencies are well known causes of hemophilia, their levels should also be measured in the workup of transplant candidates with a history of multiple vascular access thrombosis.


Assuntos
Fatores de Coagulação Sanguínea/metabolismo , Rejeição de Enxerto/etiologia , Transplante de Rim , Veias Renais , Trombose Venosa/sangue , Fator IX/análise , Fator VII/análise , Fator VIII/análise , Fator XI/análise , Sobrevivência de Enxerto , Homocisteína/sangue , Humanos , Masculino , Pessoa de Meia-Idade
3.
Can J Gastroenterol ; 14 Suppl D: 112D-121D, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11110623

RESUMO

In cirrhosis of the liver, according to the peripheral arterial vasodilation hypothesis, relative underfilling of the arterial tree triggers a neurohumoral response (activation of renin-angiotensin-aldosterone system, sympathetic nervous system, nonosmotic release of vasopressin) aimed at restoring circulatory integrity by promoting renal sodium and water retention. Evidence has accumulated for a major role of increased vascular production of nitric oxide as the primary cause of arterial vasodilation in cirrhosis. Ascites is a common complication in cirrhosis. Treatment of ascites consists of a low salt diet with diuretics, and paracentesis together with plasma volume expanders in diuretic-resistant patients. Progression of cirrhosis may result in hepatorenal syndrome, a state of functional renal failure that carries an ominous prognosis. Orthotopic liver transplantation has remained the only curative treatment for patients with advanced liver disease; other modalities such as transjugular intrahepatic portosystemic shunt or vasopressin analogues may serve as a bridge to transplantation. Another complication of decompensated cirrhosis is spontaneous bacterial peritonitis, the incidence of which can be reduced by primary or secondary antibiotic prophylaxis by using orally active antibiotics.


Assuntos
Síndrome Hepatorrenal/fisiopatologia , Cirrose Hepática/fisiopatologia , Vasodilatação/fisiologia , Aldosterona/fisiologia , Animais , Ascite/fisiopatologia , Ascite/terapia , Humanos , Cirrose Hepática/terapia , Óxido Nítrico/fisiologia , Peritonite/fisiopatologia , Prognóstico , Sistema Renina-Angiotensina/fisiologia
4.
Perit Dial Int ; 17(6): 546-53, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9655153

RESUMO

OBJECTIVE: To compare the effect of Dianeal and two newly-formulated bicarbonate-based peritoneal solutions on intracellular pH (pHi), tumor necrosis factor-alpha (TNFalpha) mRNA level, and TNFalpha secretion by peritoneal macrophages (PMphi). DESIGN AND MEASUREMENTS: Peritoneal macrophages were isolated from dialysates collected after overnight dwells in peritonitis-free continuous ambulatory peritoneal dialysis patients. Dialysis solutions contained 1.5% or 4.25% dextrose. HCO3 concentrations of bicarbonate-(TB) and bicarbonate/lactate-buffered (TBL) solution were 38 mM and 25 mM, respectively. TBL also contained lactate at a concentration of 15 mM. pCO2 levels were 78 mmHg and 51 mmHg, respectively. In all experiments pCO2 was carefully maintained at a stable level. The pHi was measured by spectrofluorometry in BCECF-loaded PMphi exposed to different dialysis solutions or Hank's balanced salt solution. TNFalpha levels were measured by ELISA in the supernatant of lipopolysaccharide- (LPS) stimulated PMphi after their incubation in different solutions for 15 and 30 minutes. TNFalpha mRNA was measured by reverse transcriptase polymerase chain reaction (RT-PCR) of total RNA extracted from LPS-stimulated PMphi after their incubation in different solutions for 30 minutes. beta-actin mRNA was used as the control. RESULTS: Dianeal caused a profound drop in pHi to below 6.2. Following an initial drop, pHi stabilized after 4 minutes at levels of 6.96 and 6.8 after incubation in TB and TBL, respectively. In comparison to the control solution, a fall of 11% and 21% in TNFalpha secretion was seen after incubation in TB for 15 and 30 minutes, respectively, and 15% and 26% after incubation in TBL. Under identical conditions, Dianeal (Baxter, McGaw Park, IL, U.S.A.) caused 59% and >95% suppression of TNFalpha secretion. Accordingly, TNFalpha mRNA level in PMphi was severely depressed by Dianeal but no detectable inhibition was observed following incubation for 30 minutes in TB and TBL. When dextrose concentration in TB and TBL was increased from 1.5% to 4.25%, TNFalpha secretion by PMphi was not suppressed by more than 49%, even after 30 minutes incubation. Moreover, suppression of TNFalpha mRNA levels could not be detected with TB or TBL even at high dextrose concentrations. CONCLUSIONS: In contrast to Dianeal, both bicarbonate-based solutions caused only a mild drop in pHi of PMphi. We postulate this effect to be responsible for the improved capacity of PMphi to secrete TNFalpha when incubated in bicarbonate-based solutions compared to Dianeal. Reflecting its known cytotoxicity, dextrose in high concentrations diminishes the protective effect of TB and TBL on immune function of PMphi. TBL is as effective as TB in preventing the deleterious effect of Dianeal on PMphi function.


Assuntos
Bicarbonatos/farmacologia , Soluções para Diálise , Macrófagos Peritoneais/efeitos dos fármacos , RNA Mensageiro/biossíntese , Fator de Necrose Tumoral alfa/genética , Materiais Biocompatíveis , Humanos , Concentração de Íons de Hidrogênio , Macrófagos Peritoneais/metabolismo , Diálise Peritoneal Ambulatorial Contínua , Fator de Necrose Tumoral alfa/metabolismo
5.
Lijec Vjesn ; 122(1-2): 20-6, 2000.
Artigo em Servo-Croata (Latino) | MEDLINE | ID: mdl-10916353

RESUMO

A decade after a unifying hypothesis of sodium and water regulation had been proposed, evidence has accumulated in support of common (patho)physiologic mechanisms of sodium and water retention in congestive heart failure, cirrhosis and pregnancy. Either primary arterial vasodilatation (cirrhosis, pregnancy), or a decrease in cardiac output (low-output heart failure) impair arterial circulatory integrity ("effective arterial blood volume"), which unloads ventricular and arterial baroreceptors. Consequently, activation of the sympathetic nervous system, renin-angiotensin-aldosterone system, arginine-vasopressin, as well as other less well explored mechanisms occurs in an attempt to restore the arterial circulatory integrity. Consequences of this neurohumoral activation with arterial uderfilling include renal sodium and water retention and an increase in peripheral vascular resistance. In this review specific pathophysiologic mechanisms underlying the sodium and water retention in congestive heart failure, cirrhosis and pregnancy will be discussed.


Assuntos
Insuficiência Cardíaca/fisiopatologia , Rim/fisiopatologia , Cirrose Hepática/fisiopatologia , Complicações na Gravidez/fisiopatologia , Sódio/metabolismo , Desequilíbrio Hidroeletrolítico/fisiopatologia , Feminino , Humanos , Gravidez
8.
Kidney Int ; 70(4): 675-81, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16788688

RESUMO

Loss of function of the peritoneal membrane is associated with peritonitis. Adenosine levels in sites of inflammation were shown to increase and exhibit immunoregulatory effects. Our aim was to elucidate the regulatory role of adenosine during peritonitis and to test the involvement of peritoneal mesothelial cells (PMC) in adenosine regulation. In a mice model of Escherichia coli peritonitis, the adenosine A(2A) receptor (A(2A)R) agonist (CGS21680) prevented leukocyte recruitment and reduced tumor necrosis factor alpha (TNF-alpha) and interleukin-6 (IL-6) levels. Peritonitis induced the elevation of adenosine with a peak at 24 h. Analysis of adenosine receptor levels on peritoneum showed that A(1) receptor (A(1)R) protein levels peak at 12 h after inoculation and then return to baseline at 24 h, whereas high affinity A(2A)R protein levels peak at 24 h concomitantly with the peak of adenosine concentration. Low affinity A(2B) receptor (A(2B)R) levels elevated slowly, remaining elevated up to 48 h. In human PMC (HPMC), the early cytokines, IL-1-alpha, and TNF-alpha upregulated the A(2B) and A(2A) receptors. However, interferon-gamma (IFN-gamma) upregulated the A(2B)R and decreased A(2A)R levels. Treatment with the A(2A)R agonist reduced IL-1-dependent IL-6 secretion from HPMC. In conclusion, the kinetics of adenosine receptors suggest that at early stage of peritonitis, the A(1)R dominates, and later its dominance is replaced by the G stimulatory (Gs) protein-coupled A(2A)R that suppresses inflammation. Early proinflammatory cytokines are an inducer of the A(2A)R and this receptor reduces their production and leukocyte recruitment. Future treatment with adenosine agonists should be considered for attenuating the damage to mesothelium during the course of acute peritonitis.


Assuntos
Adenosina/metabolismo , Inflamação/genética , Peritonite/imunologia , Peritonite/metabolismo , Receptor A1 de Adenosina/metabolismo , Receptor A2A de Adenosina/metabolismo , Adenosina/análogos & derivados , Adenosina/farmacologia , Agonistas do Receptor A1 de Adenosina , Agonistas do Receptor A2 de Adenosina , Antagonistas do Receptor A2 de Adenosina , Animais , Anti-Hipertensivos/farmacologia , Células Cultivadas , Modelos Animais de Doenças , Regulação para Baixo/efeitos dos fármacos , Regulação para Baixo/genética , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Escherichia coli , Feminino , Humanos , Interleucina-6/genética , Interleucina-6/metabolismo , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Camundongos , Camundongos Endogâmicos , Peritonite/microbiologia , Fenetilaminas/farmacologia , Agonistas do Receptor Purinérgico P1 , Antagonistas de Receptores Purinérgicos P1 , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores Purinérgicos P1/genética , Receptores Purinérgicos P1/metabolismo , Teobromina/análogos & derivados , Teobromina/farmacologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genética , Xantinas/farmacologia
9.
Am J Obstet Gynecol ; 179(6 Pt 1): 1503-10, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9855588

RESUMO

OBJECTIVE: Our purpose was to evaluate in vitro the effect of a high partial pressure of carbon dioxide environment used in laparoscopy on metabolic and immune response of various human peritoneal cells. STUDY DESIGN: Polymorphonuclear leukocytes were obtained from 5 healthy volunteers, peritoneal macrophages were obtained from the effluent of 8 patients undergoing continuous ambulatory peritoneal dialysis, and human peritoneal mesothelial cell cultures were prepared from omentum derived from 5 patients undergoing elective surgery. The cells were exposed to a laparoscopy-like environment (1 atmosphere carbon dioxide and 0.2 atmosphere oxygen), to a control gas mixture (1 atmosphere helium and 0.2 atmosphere oxygen), or air for 3 hours. After exposure to gas mixtures, cell functions were tested at various recovery periods. RESULTS: Three hours of exposure to a high partial pressure of carbon dioxide had no effect on viability of peritoneal macrophages and human peritoneal mesothelial cells, tested by trypan blue dye uptake and lactate dehydrogenase release. A high partial pressure of carbon dioxide decreased the mitochondrial dehydrogenases activity of peritoneal macrophages and human peritoneal macrophage cells by 60%, assayed by 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide reduction. High partial pressure of carbon dioxide blocked the superoxide release from activated polymorphonuclear leukocytes and the secretion of interleukin 1beta from stimulated peritoneal macrophages, and human peritoneal macrophage cells were decreased by 15% and 30% and the secretion of tumor necrosis factor-alpha from peritoneal macrophages was suppressed by 85%. Mitochondrial activity, polymorphonuclear leukocyte function, and interleukin 1beta and tumor necrosis factor-alpha secretion returned to normal after a recovery period of 12 to 24 hours, 4.5 hours, and 24 hours, respectively. In the control experiments exposure of cells to helium had no suppressive effect. CONCLUSIONS: Exposure of cells to a high partial pressure of carbon dioxide environment suppresses the inflammatory and metabolic responses of peritoneal cells. We suggest that this suppressive effect may contribute to the low postsurgery adhesion formation and the reduction in postoperative pain observed in laparoscopy. Nevertheless, the suppression of the immune response should also be taken into account for operations involving a high risk of bacterial dissemination.


Assuntos
Dióxido de Carbono/farmacologia , Macrófagos/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Peritônio/efeitos dos fármacos , Líquido Ascítico/citologia , Células Cultivadas/efeitos dos fármacos , Humanos , Interleucina-1/metabolismo , Macrófagos/metabolismo , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/enzimologia , Neutrófilos/metabolismo , Omento , Peritônio/citologia , Pneumoperitônio Artificial , Superóxidos/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
10.
Am J Nephrol ; 21(6): 494-7, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11799268

RESUMO

BACKGROUND/AIM: Few cases are found in the literature regarding autoimmune hemolytic anemia which is Coombs' test positive in kidney transplant patients, although hemolytic uremic syndrome due to cyclosporin and FK506 has been well described. In the following, we describe a case of severe life-threatening Coombs' test negative autoimmune hemolytic anemia after kidney transplantation. METHODS: Soon after undergoing renal transplantation, the patient presented with hemolytic anemia. Kidney biopsy, routine Coombs' test, gel filtration and flow-cytometric assay were undertaken. RESULTS: Kidney biopsy ruled out hemolytic uremic syndrome; although Coombs' test and gel filtration assay were negative, flow cytometry revealed circulating antierythrocytic autoantibodies. CONCLUSIONS: Our findings indicate that flow cytometry may be an efficient method in the diagnosis of hemolysis of unknown origin in transplant patients. We further hypothesize that the underlying mechanism of autoimmune hemolytic anemia is related to the passenger B lymphocytes in the graft.


Assuntos
Anemia Hemolítica Autoimune/imunologia , Transplante de Rim , Teste de Coombs , Citometria de Fluxo , Humanos , Imunossupressores/efeitos adversos , Masculino , Pessoa de Meia-Idade , Plasmaferese
11.
Kidney Int ; 57(2): 476-86, 2000 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-10652024

RESUMO

BACKGROUND: To assess the role of human peritoneal mesothelial cells (HPMCs) in the generation of an immune response during peritonitis, we tested their ability to activate T-cells by antigen presentation (AP) and by the secretion of interleukin-15 (IL-15). IL-15 is a potent leukocyte activator that stimulates the proliferation of CD4+, CD8+, and B and natural killer (NK) cells. METHODS: HPMCs and mononuclear cells were derived from six volunteer patients who underwent elective abdominal surgery. Flow cytometry was used to analyze human lymphocyte antigen-DR (HLA-DR), intercellular adhesion molecule-1 (ICAM-1), and B7 molecules on HPMCs. Affinity-purified CD4 cells were used for AP assays. We used a specific enzyme-linked immunosorbent assay to detect interferon-gamma (IFN-gamma), IL-2, and IL-15 protein and reverse transcription-polymerase chain reaction for mRNA analysis. RESULTS: HPMCs expressed HLA-DR molecules following IFN-gamma treatment. ICAM-1 molecules were expressed at high levels, and B7-1 and B7-2 molecules could not be detected. The accessory function of HPMCs was assayed by T-cell stimulation using anti-CD3 antibodies (OKT3). HPMCs were essential for a significant OKT3-induced T-cell proliferation. Anti-ICAM-1 antibodies blocked OKT3-induced proliferation. HPMCs served as effective antigen-presenting cells when Tetanus toxoid (TT) or Staphylococcus aureus-alpha-toxin were used as antigens. IFN-gamma, IL-2, and IL-15 accumulated during AP reactions. We found that IL-15 is produced by HPMCs, and IFN-gamma up-regulated its mRNA levels and protein secretion in a dose-dependent manner. We also detected IL-15 in the peritoneal effluent of patients undergoing continuous peritoneal dialysis treatment. In patients suffering from peritonitis, IL-15 levels were elevated (35.0 +/- 6.0 pg/mL, N = 10) as compared with noninfected patients (16.2 +/- 4.0 pg/mL, N = 7). CONCLUSIONS: HPMCs participate in the peritoneal immune response against invading pathogens by AP. For this process, ICAM-1 is the major accessory molecule. In addition, HPMCs may contribute to T-cell activation by secretion of IL-15.


Assuntos
Apresentação de Antígeno/imunologia , Linfócitos T CD4-Positivos/citologia , Células Epiteliais/imunologia , Peritônio/citologia , Adulto , Toxinas Bacterianas/imunologia , Linfócitos T CD4-Positivos/imunologia , Divisão Celular/imunologia , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Feminino , Citometria de Fluxo , Expressão Gênica/imunologia , Antígeno HLA-B7/análise , Antígenos HLA-DR/análise , Proteínas Hemolisinas/imunologia , Humanos , Imunossupressores/farmacologia , Molécula 1 de Adesão Intercelular/análise , Interferon gama/farmacologia , Interleucina-15/genética , Interleucina-15/imunologia , Interleucina-15/metabolismo , Falência Renal Crônica/imunologia , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Muromonab-CD3/farmacologia , Sondas de Oligonucleotídeos , Diálise Peritoneal Ambulatorial Contínua , Peritônio/imunologia , Peritonite/imunologia , Peritonite/metabolismo , RNA Mensageiro/análise , Toxoide Tetânico/imunologia
12.
Urol Nefrol (Mosk) ; (6): 41-4, 1989.
Artigo em Russo | MEDLINE | ID: mdl-2617737

RESUMO

Altogether 34 patients with the nephrotic syndrome (NS) of chronic glomerulonephritis (CGN) were studied for lithium clearance (CLi). Eleven patients with edemas were enrolled in group I, 18 subjects without pronounced edemas, in group II. Out of them 7 patients suffered from membrane proliferative glomerulonephritis (group III), 7, from mesangioproliferative glomerulonephritis (group IV), 4 subjects had focal glomerulosclerosis (group V); chronic renal failure (CRF), stages IIb-IIIa, was diagnosed in 7 patients enlisted in group VI. The control group consisted of 11 virtually healthy persons. On the CLi basis the authors identified the proximal excretory water fraction (EFpH2O), the distal excretory fraction of the water (EFdH2O) and the distal excretory fraction of sodium (EFdNa). The controls demonstrated the mean values of the parameters considered: 16.18 +/- 1.56 ml/min; 19.88 +/- 1.63; 7.19 +/- 1.16 and 4.38 +/- 7.76 per cent, respectively. Decreased CLi was revealed in groups I and II. Versus the controls patients enrolled in group II demonstrated a significant decrease of EFpH2O (11.91 +/- 2.22 per cent; p less than 0.05) and an increase of EFdH2O (16.81 +/- 3.26 per cent; p less than 0.05). A great individual variance of the parameters considered (from 1.32 to 55.63 per cent and from 2.33 to 118 per cent, respectively) hindered to reveal the difference between group I and the controls.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Glomerulonefrite/metabolismo , Néfrons/metabolismo , Sódio/metabolismo , Água/metabolismo , Transporte Biológico , Edema/metabolismo , Glomerulonefrite/complicações , Humanos , Falência Renal Crônica/metabolismo , Lítio/metabolismo , Síndrome Nefrótica/etiologia , Síndrome Nefrótica/metabolismo
13.
Am J Physiol Renal Physiol ; 279(6): F1110-5, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11097630

RESUMO

Cirrhosis is typically associated with a hyperdynamic circulation consisting of low blood pressure, low systemic vascular resistance (SVR), and high cardiac output. We have recently reported that nonspecific inhibition of nitric oxide synthase (NOS) with nitro-L-arginine methyl ester reverses the hyperdynamic circulation in rats with advanced liver cirrhosis induced by carbon tetrachloride (CCl(4)). Although an important role for endothelial NOS (eNOS) is documented in cirrhosis, the role of neuronal NOS (nNOS) has not been investigated. The present study was carried out to specifically investigate the role of nNOS during liver cirrhosis. Specifically, physiological, biochemical, and molecular approaches were employed to evaluate the contribution of nNOS to the cirrhosis-related hyperdynamic circulation in CCl(4)-induced cirrhotic rats with ascites. Cirrhotic animals had a significant increase in water and sodium retention. In the aorta from cirrhotic animals, both nNOS protein expression and cGMP concentration were significantly elevated compared with control. Treatment of cirrhotic rats for 7 days with the specific nNOS inhibitor 7-nitroindazole (7-NI) normalized the low SVR and mean arterial pressure, elevated cardiac index, and reversed the positive sodium balance. Increased plasma arginine vasopressin concentrations in the cirrhotic animals were also repressed with 7-NI in association with diminished water retention. The circulatory changes were associated with a reduction in aortic nNOS expression and cGMP. However, 7-NI treatment did not restore renal function in cirrhotic rats (creatinine clearance: 0.76 +/- 0.03 ml. min(-1). 100 g body wt(-1) in cirrhotic rats vs. 0.79 +/- 0.05 ml. min(-1). 100 g body wt(-1) in cirrhotic rats+7-NI; P NS. ). Taken together, these results indicate that nNOS-derived NO contributes to the development of the hyperdynamic circulation and fluid retention in cirrhosis.


Assuntos
Cirrose Hepática Experimental/enzimologia , Óxido Nítrico Sintase/metabolismo , Vasodilatação/fisiologia , Animais , Arginina Vasopressina/sangue , Ascite/metabolismo , Western Blotting , GMP Cíclico/metabolismo , Inibidores Enzimáticos/farmacologia , Hemodinâmica/efeitos dos fármacos , Hemodinâmica/fisiologia , Indazóis/farmacologia , Rim/efeitos dos fármacos , Rim/metabolismo , Testes de Função Renal , Masculino , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/biossíntese , Óxido Nítrico Sintase Tipo I , Concentração Osmolar , Ratos , Ratos Sprague-Dawley , Sódio/urina
14.
Am J Physiol Renal Physiol ; 280(4): F592-8, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11249850

RESUMO

The chronic role of nitric oxide (NO), independent of prostaglandin synthesis, in the primary peripheral vasodilation, increased glomerular filtration rate (GFR), and renal plasma flow (RPF) in normal pregnancy remains to be defined. The purpose of the present study was to chronically inhibit NOS to return systemic vascular resistance (SVR), cardiac output (CO), GFR, and RPF to nonpregnant values. Pregnant rats received the nitric oxide synthase (NOS) inhibitor, nitro-L-arginine methyl ester (L-NAME), orally from gestational days 7 through 14. Results were compared with nonpregnant and untreated pregnant rats. At 14 days gestation, CO significantly increased in pregnant vs. nonpregnant rats (187 +/- 17 vs. 125 +/- 10 ml/min, P < 0.05) as SVR decreased (0.64 +/- 0.08 vs. 1.08 +/- 0.08 mmHg. ml(-1). min, P < 0.05) and mean arterial pressure was unchanged (117 +/- 5 vs. 125 +/- 2 mmHg, not significant). Pregnant rats also demonstrated increased GFR (3,015 +/- 33 vs. 2,165 +/- 136 microl/min, P < 0.01) and RPF (7,869 +/- 967 vs. 5,507 +/- 290 microl/min, P < 0.05) vs. nonpregnant rats. L-NAME-treated pregnant rats had values for CO (118 +/- 7 ml/min), SVR (1.09 +/- 0.07 mmHg. ml(-1). min), GFR (2,264 +/- 150 microl/min), and RPF (5,777 +/- 498 microl/min), which were no different than nonpregnant animals. In summary, similar to human pregnancy, primary peripheral vasodilation occurs early in rat pregnancy. Furthermore, the hyperdynamic circulation and glomerular hyperfiltration of normal rat midterm pregnancy can be chronically reversed by NOS inhibition. These findings suggest a role for endothelial damage and decreased NO in the pathogenesis of preeclampsia.


Assuntos
Glomérulos Renais/irrigação sanguínea , Glomérulos Renais/enzimologia , Óxido Nítrico Sintase/antagonistas & inibidores , Prenhez/metabolismo , Vasodilatação/fisiologia , Animais , Ingestão de Líquidos/fisiologia , Inibidores Enzimáticos/farmacologia , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Taxa de Filtração Glomerular/fisiologia , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/sangue , Óxido Nítrico Sintase/metabolismo , Gravidez , Ratos , Ratos Sprague-Dawley , Circulação Renal/efeitos dos fármacos , Circulação Renal/fisiologia , Vasodilatação/efeitos dos fármacos
15.
Kidney Int ; 59(6): 2243-9, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11380827

RESUMO

BACKGROUND: Renal failure is a frequent complication of sepsis with a high mortality. Tumor necrosis factor (TNF) has been suggested to be a factor in the acute renal failure in sepsis or endotoxemia. Recent studies also suggest involvement of nitric oxide (NO), generated by inducible NO synthase (iNOS), in the pathogenesis of endotoxin-induced renal failure. The present study tested the hypothesis that the role of TNF in endotoxic renal failure is mediated by iNOS-derived NO. METHODS: Renal function was evaluated in endotoxemic [Escherichia coli lipopolysaccharide (LPS), 5 mg/kg IP] wild-type and iNOS knockout mice. The effect of TNF neutralization on renal function during endotoxemia in mice was assessed by a TNF-soluble receptor (TNFsRp55). RESULTS: An injection of LPS to wild-type mice resulted in a 70% decrease in glomerular filtration rate (GFR) and in a 40% reduction in renal plasma flow (RPF) 16 hours after the injection. The results occurred independent of hypotension, morphological changes, apoptosis, and leukocyte accumulation. In mice pretreated with TNFsRp55, only a 30% decrease in GFR without a significant change in RPF in response to LPS, as compared with vehicle-treated mice, was observed. Also, the serum NO concentration was significantly lower in endotoxemic wild-type mice pretreated with TNFsRp55, as compared with untreated endotoxemic wild-type mice (260 +/- 52 vs. 673 +/- 112 micromol/L, P < 0.01). In LPS-injected iNOS knockout mice and wild-type mice treated with a selective iNOS inhibitor, 1400W, the development of renal failure was similar to that in wild-type mice. As in wild-type mice, TNFsRp55 significantly attenuated the decrease in GFR (a 33% decline, as compared with 75% without TNFsRp55) without a significant change in RPF in iNOS knockout mice given LPS. CONCLUSIONS: These results demonstrate a role of TNF in the early renal dysfunction (16 h) in a septic mouse model independent of iNOS, hypotension, apoptosis, leukocyte accumulation, and morphological alterations, thus suggesting renal hypoperfusion secondary to an imbalance between, as yet to be defined, renal vasoconstrictors and vasodilators.


Assuntos
Injúria Renal Aguda/metabolismo , Endotoxemia/complicações , Óxido Nítrico Sintase/genética , Fator de Necrose Tumoral alfa/metabolismo , Injúria Renal Aguda/etiologia , Animais , Antígenos CD/farmacologia , Apoptose , Pressão Sanguínea , Taxa de Filtração Glomerular , Hipertensão Renal/etiologia , Hipertensão Renal/metabolismo , Rim/irrigação sanguínea , Rim/enzimologia , Leucócitos , Lipopolissacarídeos/toxicidade , Masculino , Camundongos , Camundongos Knockout , Óxido Nítrico/sangue , Óxido Nítrico Sintase/metabolismo , Óxido Nítrico Sintase Tipo II , Receptores do Fator de Necrose Tumoral , Receptores Tipo I de Fatores de Necrose Tumoral , Vasoconstrição/fisiologia
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