Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Asian Spine J ; 17(5): 818-825, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37788972

RESUMO

STUDY DESIGN: This study adopted a retrospective cohort study design. PURPOSE: This study aimed to clarify the influence of diffuse idiopathic skeletal hyperostosis (DISH) on bone fusion after transforaminal lumbar interbody fusion (TLIF). OVERVIEW OF LITERATURE: The negative effects of DISH on lumbar degenerative diseases have been reported, and DISH may be involved in the onset and severity of lumbar spinal canal stenosis. Patients with DISH have significantly more reoperations after posterior lumbar fusion, including TLIF. However, the effects of DISH on bone fusion after TLIF have not been reported. METHODS: The medical records of patients with intervertebral TLIF from 2012 to 2018 were retrospectively examined. The patients were divided into those with fusion and those with pseudoarthrosis, and the following data were compared: age, sex, DISH, diabetes mellitus, smoking, drinking, albumin levels, body mass index ≥30 kg/m2, and L5/S fixation. Statistical analyses were performed using regression models. RESULTS: In this study, 180 patients (78.6%) had fusion and 49 patients (21.4%) had pseudoarthrosis. The number of patients with DISH was significantly higher in the pseudoarthrosis group than in the fusion group (36.7% and 21.7%, respectively; univariate p=0.031, multivariate p =0.019). No significant differences in age, sex, diabetes mellitus, smoking, drinking, albumin levels, body mass index ≥30 kg/m2, and L5/S fixation were observed between the two groups. The risk factors for bone fusion were statistically analyzed in 57 patients with DISH. DISH with a caudal end below Th11 was an independent risk factor for pseudoarthrosis (univariate p=0.011, multivariate p=0.033). CONCLUSIONS: DISH is an independent risk factor for pseudoarthrosis after one intervertebral TLIF, and DISH with a caudal end below Th11 is associated with a higher risk of pseudoarthrosis than DISH without a caudal end below Th11.

2.
Eur J Prev Cardiol ; 30(18): 1941-1949, 2023 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-37352112

RESUMO

AIMS: Cancer treatment-related cardiovascular toxicity (CTR-CVT) is a growing concern in patients undergoing anticancer therapy. The Heart Failure Association (HFA) and International Cardio-Oncology Society (ICOS) risk assessment tools have been proposed for the baseline cardiovascular (CV) risk stratification of patients with cancer. This study investigated the incidence of CV adverse events in clinical practice, also using the HFA-ICOS risk tool. METHODS AND RESULTS: This single-centre, prospective, observational study was conducted at Kurume University Hospital from October 2016 to August 2021, including patients aged ≥20 years with haematologic malignancies or breast cancer who were receiving anticancer agents. Cardiovascular assessments were performed at enrolment and every 6 months until August 2021, with additional assessments for suspected CV adverse events. The primary endpoint was common terminology criteria for adverse events v4.0 Grade ≥2, and the secondary endpoints were all-cause and CV deaths. Of the enrolled 486 patients, CV adverse events occurred in 24.5, 15.8, 38.1, and 18.0% of patients with leukaemia, malignant lymphoma, multiple myeloma, and breast cancer, respectively. Patients at high or very high risk had a significantly higher incidence of CV events, according to the HFA-ICOS risk tool. Cardiovascular death occurred in 4 (0.8%) patients during follow-up. CONCLUSION: This study revealed that 16-38% of patients with haematologic malignancies and breast cancer developed CTR-CVT during follow-up, in which patients with high/very high risk were well predicted by the HFA-ICOS risk assessment tool. Monitoring and managing CV risk factors are essential for safe cancer therapy.


As the elderly population grows worldwide, cancer and cardiac diseases have become the leading causes of death in many countries, including Japan. With advances in cancer treatment, survival rates have improved, resulting in an increasing number of cancer survivors developing therapy-related cardiovascular (CV) problems. The study, conducted at Kurume University Hospital, examined 486 participants with haematologic malignancies and breast cancer. The result demonstrates CV adverse events in 12, 45, 24, and 16 patients with leukaemia, malignant lymphoma, multiple myeloma, and breast cancer, respectively. Heart failure and left ventricular systolic dysfunction were the most common adverse events. This study demonstrates the importance of monitoring patients with cancer for potential CV risks and highlights the need for further research to improve treatment protocols for those at higher risk. Key findings include This prospective study conducted in Japan revealed a high incidence of adverse cardiovascular (CV) events in patients with haematologic malignancies and breast cancer treated with anticancer agents but a low CV mortality rate during the mid-term follow-up period. Patients at high/very high risk, as determined by the Heart Failure Association-International Cardio-Oncology Society risk assessment tool, experienced a higher incidence of CV events and heart failure compared with those at low and moderate risks.


Assuntos
Antineoplásicos , Neoplasias da Mama , Insuficiência Cardíaca , Neoplasias Hematológicas , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/epidemiologia , Estudos Prospectivos , Antineoplásicos/efeitos adversos , Neoplasias Hematológicas/diagnóstico , Neoplasias Hematológicas/tratamento farmacológico , Neoplasias Hematológicas/epidemiologia , Prognóstico , Insuficiência Cardíaca/tratamento farmacológico , Sistema de Registros
3.
Kurume Med J ; 68(2): 141-144, 2023 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-37005291

RESUMO

Vanishing tumor of the lung, also known as phantom tumor, is uncommonly observed in congestive heart failure. We report a case of a vanishing tumor that rapidly disappeared and reappeared in just a few minutes due to repositioning in a patient after open-heart surgery.


Assuntos
Procedimentos Cirúrgicos Cardíacos , Insuficiência Cardíaca , Neoplasias Pulmonares , Humanos , Pulmão , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Neoplasias Pulmonares/cirurgia
4.
Nephrol Dial Transplant ; 37(1): 115-125, 2021 12 31.
Artigo em Inglês | MEDLINE | ID: mdl-34282462

RESUMO

BACKGROUND: Fabry disease (FD), an X-linked lysosomal storage disorder caused by a deficiency in alfa-galactosidase A (α-Gal A) activity due to mutations in the GLA gene, has a prevalence of 0-1.69% in patients undergoing haemodialysis; however, its prevalence in patients with chronic kidney disease (CKD) Stages 1-5 is unknown. METHODS: Serum α-Gal A activity analysis and direct sequencing of GLA were used to screen for FD in 2122 male patients with CKD, including 1703 patients with CKD Stage 5D and 419 with CKD Stages 1-5. The correlation between serum α-Gal A activity and confounding factors in patients with CKD Stages 1-5 was evaluated. RESULTS: FD prevalence rates in patients with CKD Stage 5D and CKD Stages 1-5 were 0.06% (1/1703) and 0.48% (2/419), respectively. A patient with CKD Stage 5D exhibited a novel GLA mutation, p.Met208Arg, whereas two patients with CKD Stages 1-5 had c.370delG and p.Met296Ile. p. Met208Arg caused moderate structural changes in the molecular surface region near the substituted amino acid residue but did not affect the catalytic residues Asp170 and Asp231 in α-Gal A. Serum α-Gal A activity in patients with CKD Stages 1-5 was inversely correlated with age (P < 0.0001) but directly correlated with estimated glomerular filtration rate (P < 0.0001). CONCLUSIONS: FD prevalence was much higher in male patients with CKD Stages 1-5 than in those with CKD Stage 5D. FD screening in patients with CKD Stages 1-5 may improve patient survival, decreasing the number of patients with CKD Stage 5D.


Assuntos
Doença de Fabry , Insuficiência Renal Crônica , Doença de Fabry/complicações , Doença de Fabry/diagnóstico , Doença de Fabry/epidemiologia , Humanos , Japão/epidemiologia , Masculino , Mutação , Diálise Renal , Insuficiência Renal Crônica/epidemiologia , alfa-Galactosidase/genética
5.
Clin Neurol Neurosurg ; 206: 106696, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34059400

RESUMO

OBJECTIVE: To evaluate the improvement of drop foot following lumbar decompression surgery and determine the prognostic factors that might influence the recovery of drop foot. SUMMARY AND BACKGROUND DATE: Drop foot is a common but serious problem that can lead to deteriorate patient's daily activities. There are numerous studied regarding the prognostic factors for the recovery of drop foot. However a few reports have been described the pathophysiological etiology of not only drop foot but also Trendelenburg's sign due to the L5 nerve root palsy. Therefore, there is a possibility drop foot caused by peroneal nerve palsy is included. In addition, none have evaluated the presence or absence of radicular leg pain with drop foot patients. The purpose of this study was to evaluate the improvement of paretic leg muscles and determine the prognostic factors that might influence the recovery of drop foot. METHODS: Fifty-five drop foot patients were included in the study. Prognostic factors were retrospectively studied.Patients were assessed in terms of 10 items: 1) age, 2) sex, 3) diagnosis (LDH or LSS), 4) muscle strength of tibialis anterior, 5) muscle strength of extensor halluces longus, 6) muscle strength of gluteus medius, 7) presence or absence of radicular leg pain, 8) duration before surgery, 9) surgical treatment (spinal fusion or not), 10) anamnesis of diabetes mellitus. RESULTS: Thirty-two (58.2%) of 55 patients recovered from their drop foot (manual muscle test of tibialis anterior ≥ 4 at final follow-up), while 23 (41.8%) did not (manual muscle test of tibialis anterior ≤ 3 at final follow-up). The strength of all muscles that were innervated and controlled by the L5 nerve root had recovered at the final follow-up when evaluated as averages. Multivariate logistic regression analysis revealed significant differences in terms of 2 items: "duration before surgery" and "presence or absence of radicular leg pain". CONCLUSIONS: "Duration before surgery" and "presence or absence of radicular leg pain" are important to predict the recovery of drop foot. Painless drop foot patients with lumbar degenerative disease are difficult to recover their paralysis.


Assuntos
Degeneração do Disco Intervertebral/complicações , Degeneração do Disco Intervertebral/cirurgia , Neuropatias Fibulares/etiologia , Recuperação de Função Fisiológica , Adulto , Idoso , Idoso de 80 Anos ou mais , Descompressão Cirúrgica , Feminino , Humanos , Vértebras Lombares , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos
6.
Intern Med ; 60(5): 755-759, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33028772

RESUMO

Keishibukuryogan is a Kampo medicine that induces vasodilation and improves the blood flow velocity in subcutaneous blood vessels. We herein report two cases in which keishibukuryogan completely diminished subcutaneous hematoma after cardiac resynchronization therapy pacemaker implantation and defibrillator battery replacement within a month. Keishibukuryogan can be a good option for treating or preventing subcutaneous hematoma after surgical procedures for devices.


Assuntos
Terapia de Ressincronização Cardíaca , Desfibriladores Implantáveis , Medicamentos de Ervas Chinesas , Marca-Passo Artificial , Desfibriladores Implantáveis/efeitos adversos , Hematoma/diagnóstico por imagem , Hematoma/etiologia , Humanos , Marca-Passo Artificial/efeitos adversos
7.
Ther Apher Dial ; 25(3): 304-313, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32777142

RESUMO

Serum carnitine is decreased in hemodialysis patients, which induces muscle atrophy. Thus, we examined the different effects of l-carnitine and exercise on exercise activity and muscle status in hemodialysis patients. Twenty patients were divided into l-carnitine and cycle ergometer groups and were followed for 3 months. Muscle and fat mass, physical activities, and muscle status were evaluated by an impedance, physical function test, and magnetic resonance imaging, respectively. The l-carnitine significantly increased muscle mass (P = .023) and thigh circumference (P = .027), decreased fat mass (P = .007), and shortened chair stand-up time (P = .002) and 10-m walk test (P = .037). The fat fraction was improved by the l-carnitine (P = .047). Compared with the exercise group, l-carnitine improved the changes in 10-m walk test (P = .026), chair stand-up time (P = .014), and thigh circumference (P = .022). Baseline fibroblast growth factor-21 and myostatin levels predicted the l-carnitine-associated changes in exercise activities. l-carnitine, rather than exercise, improved physical activity and muscle status in hemodialysis patients.


Assuntos
Carnitina/administração & dosagem , Suplementos Nutricionais , Teste de Esforço/métodos , Exercício Físico/fisiologia , Músculos/efeitos dos fármacos , Diálise Renal , Carnitina/sangue , Teste de Esforço/estatística & dados numéricos , Feminino , Humanos , Japão , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Músculos/diagnóstico por imagem , Músculos/fisiologia , Estudos Prospectivos
8.
CEN Case Rep ; 8(3): 205-211, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30927247

RESUMO

A 65-year-old male patient with nephrotic syndrome was admitted to our hospital due to worsening systemic edema and purpura on the limbs. He had an impaired renal function, low serum complement level, and elevated rheumatoid factor level. He was positive for cryoglobulin (monoclonal IgM-κ and polyclonal mixed-type IgG), and the results of his kidney biopsy showed a tissue profile of membranoproliferative glomerulonephritis (MPGN). Due to the fact that the secondary cause was unclear, he was diagnosed with MPGN due to essential mixed cryoglobulinemia. On hospital day 20, he was initiated on 50 mg/day prednisolone (PSL). On hospital day 43, oral mizoribine (MZR) at a dose of 150 mg/day was prescribed. On hospital day 49, cryofiltration was performed because the disease was steroid resistant. The treatment promptly decreased urine protein levels. Serum albumin and serum complement levels increased, and complete remission was achieved approximately three months after the initiation of treatment. The PSL and MZR doses were gradually reduced to 2 mg/day and 100 mg/day, respectively, without any reemergence of the symptoms of cryoglobulinemia or relapse of the nephrotic syndrome for three years. Here, we report this case with essential mixed cryoglobulinemia in whom we could achieve complete remission of the disease by adding cryofiltration to the oral corticosteroid and immunosuppressant therapy with mizoribine and could maintain for a long time.


Assuntos
Remoção de Componentes Sanguíneos , Crioglobulinemia/complicações , Glomerulonefrite Membranoproliferativa/terapia , Imunossupressores/uso terapêutico , Ribonucleosídeos/uso terapêutico , Idoso , Glomerulonefrite Membranoproliferativa/etiologia , Glomerulonefrite Membranoproliferativa/patologia , Glucocorticoides/uso terapêutico , Humanos , Rim/patologia , Masculino , Prednisolona/uso terapêutico
9.
CEN Case Rep ; 7(1): 48-54, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29181824

RESUMO

We report a case of smoking-related idiopathic nodular glomerulosclerosis (ING) with overexpression of glomerular advanced glycation end products (AGEs) and their receptor (RAGE). A 59-year-old Japanese man with nephrotic syndrome, who had a smoking history of one pack of cigarettes per day for approximately 40 years, presented with a 3-year history of urinalysis abnormalities without clinical evidence of diabetic mellitus. The patient's leg edema progressively worsened over the previous 2 years, and he was admitted to our hospital. Renal biopsy showed mesangial expansion with diabetic Kimmelstiel-Wilson-like nodular lesions, glomerular basement thickening, and arteriosclerosis. No electron-dense deposits, fibrils, or microtubule deposits were seen in the glomeruli on electron microscopy. Skin AGE level measured using AGE reader was higher in this case than the average level in age-matched Caucasians. In addition, immunohistochemical analysis revealed that N-carboxymethyl lysine, one of the major AGEs, and RAGE were overexpressed and podocin expression was decreased in the peripheral area of the glomerular nodular lesions. These observations suggest that AGEs-RAGE system may be activated in smoking-related ING, possibly leading to the progression of renal dysfunction.

10.
Nephrol Dial Transplant ; 24(4): 1162-9, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19015171

RESUMO

BACKGROUND: Decreased peritubular capillary (PTC) flow due to impaired endothelial function elicits tubulointerstitial ischaemia, thereby enhancing renal damage in chronic kidney disease, including diabetic nephropathy. Since nitric oxide (NO) is a vasodilator and known to play an important role in the maintenance of PTC flow, it is conceivable that asymmetric dimethylarginine (ADMA), an endogenous inhibitor of NO synthase, may cause tubulointerstitial ischaemia, thus being involved in the progression of diabetic nephropathy. In this study, we investigated whether overexpression of dimethylarginine dimethylaminohydrolase (DDAH), an enzyme that degrades ADMA, could improve tubulointerstitial ischaemia in streptozotocin (STZ)-induced diabetic rats. METHODS: Recombinant adenovirus vector encoding DDAH-I (Adv-DDAH) or control vector expressing bacterial beta-galactosidase (Adv-LZ) was intravenously administrated to diabetic rats. Three days after the treatment, effects of DDAH overexpression on plasma or urinary levels of ADMA or NO metabolites (NOx), tubulointerstitial ischaemia and renal expression of transforming growth factor-beta (TGF-beta) were evaluated. RESULTS: Renal DDAH expression and activity were reduced in diabetic rats. Urinary levels of ADMA and TGF-beta were increased, while NOx levels were decreased in diabetic rats. Compared with control rats, pimonidazole-detected hypoxic areas were larger in the kidney of diabetic rats, although the number of capillaries in tubulointerstitial regions was not different between the two groups. In addition, renal expression levels of hypoxia-inducible factor-1alpha (HIF-1alpha) and TGF-beta were also increased in diabetic rats. DDAH overexpression significantly inhibited the increase of ADMA and the decrease of NOx and subsequently decreased urinary albumin excretion levels and ameliorated tubulointerstitial hypoxia and HIF-1alpha as well as TGF-beta expression in diabetic rats. CONCLUSION: The present study demonstrated for the first time that the suppression of ADMA by DDAH overexpression could improve tubulointerstitial ischaemia and subsequent renal damage in experimental diabetic nephropathy. Substitution of DDAH protein or enhancement of its activity may become a novel therapeutic strategy for the treatment of early diabetic nephropathy.


Assuntos
Arginina/análogos & derivados , Nefropatias Diabéticas/fisiopatologia , Isquemia/fisiopatologia , Rim/irrigação sanguínea , Adenoviridae , Amidoidrolases/biossíntese , Animais , Arginina/antagonistas & inibidores , Arginina/fisiologia , Modelos Animais de Doenças , Vetores Genéticos , Masculino , Nefrite Intersticial/fisiopatologia , Óxido Nítrico/antagonistas & inibidores , Ratos , Ratos Sprague-Dawley
11.
Nephrol Dial Transplant ; 24(5): 1397-406, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19042927

RESUMO

BACKGROUND: Pigment epithelium-derived factor (PEDF) is a glycoprotein with potent neuronal differentiating activity. We, along with others, have recently found that PEDF inhibits retinal hyperpermeability by counteracting the biological effects of vascular endothelial growth factor (VEGF). However, the protective role of PEDF against nephrotic syndrome (NS), a condition of hyperpermeability in the glomerular capillaries, remains to be elucidated. In this study, we investigated whether and how PEDF reduced proteinuria in rats with adriamycin (ADR)-induced nephropathy (ADN), an experimental model of NS. METHODS: ADN was induced by a single intravenous injection of doxorubicin hydrochloride (n = 12). Half the ADN rats were intravenously administrated human recombinant PEDF; the other half were given vehicle everyday for up to 14 days. Control rats (n = 6) received vehicle only. RESULTS: In ADN, expression levels of PEDF in isolated glomeruli were significantly decreased, which were associated with a marked proteinuria and increased urinary excretion of nephrin, an index of podocyte damage. Loss of nephrin and decreased podocyte cell number and fusion of foot processes of podocytes with nuclear factor-kappa B (NF-kappaB) activation and VEGF overexpression were also observed in the glomeruli of rats with ADN. Intravenous administration of PEDF ameliorated all of these changes in ADN rats. CONCLUSION: The present findings suggest that PEDF could reduce proteinuria by suppressing podocyte damage and decreased nephrin as well as increased VEGF expression in the glomeruli of ADN rats. Pharmacological up-regulation or substitution of PEDF may offer a promising therapeutic strategy for the treatment of nephrotic syndrome.


Assuntos
Proteínas do Olho/uso terapêutico , Glomérulos Renais/metabolismo , Proteínas de Membrana/urina , Síndrome Nefrótica/metabolismo , Fatores de Crescimento Neural/uso terapêutico , Proteinúria/tratamento farmacológico , Proteínas Recombinantes/uso terapêutico , Serpinas/uso terapêutico , Fator A de Crescimento do Endotélio Vascular/metabolismo , Animais , Modelos Animais de Doenças , Doxorrubicina , Proteínas do Olho/metabolismo , Proteínas do Olho/farmacologia , Humanos , Injeções Intravenosas , Glomérulos Renais/efeitos dos fármacos , Glomérulos Renais/patologia , Masculino , NF-kappa B/metabolismo , Síndrome Nefrótica/induzido quimicamente , Síndrome Nefrótica/patologia , Fatores de Crescimento Neural/metabolismo , Fatores de Crescimento Neural/farmacologia , Podócitos/efeitos dos fármacos , Podócitos/metabolismo , Podócitos/patologia , Proteinúria/metabolismo , Proteinúria/patologia , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/farmacologia , Serpinas/metabolismo , Serpinas/farmacologia
12.
J Am Soc Nephrol ; 18(5): 1525-33, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17409314

RESUMO

Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, is mainly degraded by dimethylarginine dimethylaminohydrolase (DDAH). It was recently reported that reduced DDAH expression could contribute to ADMA accumulation and subsequent elevation of BP in an experimental model of chronic kidney disease (CKD). ADMA is a strong predictor of the progression of CKD as well. However, a role for the ADMA-DDAH in the pathogenesis of CKD remains to be elucidated. This study investigated the effects of DDAH-elicited ADMA lowering on renal function and pathology in a rat remnant kidney model. Four weeks after five-sixths subtotal nephrectomy (Nx), the rats were given tail-vein injections of recombinant adenovirus vector encoding DDAH-I (Adv-DDAH) or control vector expressing bacterial beta-galactosidase (Adv-LZ) or orally administered 20 mg/kg per d hydralazine (Hyz), which served as a BP control model. In comparison with Adv-LZ or Hyz administration, Adv-DDAH decreased plasma levels of ADMA and inhibited the deterioration of renal dysfunction. Plasma levels of ADMA were associated with decreased number of peritubular capillaries, increased tubulointerstitial fibrosis, and proteinuria levels in Nx rats. These changes were progressed in Adv-LZ-or Hyz-treated Nx rats, which were ameliorated by DDAH overexpression. In addition, semiquantitative reverse transcriptase-PCR and immunohistochemistry for TGF-beta revealed that Adv-DDAH inhibited upregulation of TGF-beta expression in Nx rats. These data suggest that ADMA may be involved in peritubular capillary loss and tubulointerstitial fibrosis, thereby contributing to the progression of CKD. Substitution of DDAH protein or enhancement of its activity may become a novel therapeutic strategy for the treatment of CKD.


Assuntos
Amidoidrolases/fisiologia , Nefropatias/patologia , Rim/irrigação sanguínea , Rim/fisiopatologia , Amidoidrolases/genética , Animais , Arginina/análogos & derivados , Arginina/sangue , Capilares/patologia , Doença Crônica , Modelos Animais de Doenças , Progressão da Doença , Fibrose , Regulação Enzimológica da Expressão Gênica , Terapia Genética , Rim/enzimologia , Nefropatias/enzimologia , Nefropatias/genética , Masculino , Ratos , Ratos Sprague-Dawley , Fator de Crescimento Transformador beta/farmacologia
13.
J Am Soc Nephrol ; 17(8): 2176-83, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16807406

RESUMO

Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide synthase. ADMA is generated by protein methyltransferase (PRMT) and is metabolized mainly by dimethylarginine dimethylaminohydrolase (DDAH). ADMA levels are reported to increase in patients with chronic kidney disease (CKD), thereby playing a role in the pathogenesis of accelerated atherosclerosis in this population. However, the precise mechanism underlying ADMA accumulation in these patients is not fully understood. This study investigated the molecular mechanism for the elevation of ADMA levels in CKD, using a rat remnant kidney model that represents progressive CKD. After male Sprague-Dawley rats underwent baseline measurement of BP and renal function, 5/6 subtotal nephrectomy (5/6Nx) and 4/6 nephrectomy were performed. Plasma and urinary levels of ADMA and symmetric dimethylarginine, an inert isomer of ADMA, were measured by HPLC. Expression levels of PRMT genes and DDAH proteins were analyzed by semiquantitative reverse transcription-PCR and Western blotting, respectively. Plasma ADMA levels were elevated in the Nx groups in proportion to the degree of nephrectomy despite marked increases in renal clearance of ADMA. In contrast, renal clearance of symmetric dimethylarginine was decreased and its plasma levels were increased in the Nx groups. Furthermore, both liver and kidney gene expression of PRMT was increased, whereas DDAH protein expression was decreased in the 5/6Nx group. Plasma ADMA levels were correlated with systolic BP levels. Moreover, adenovirus-mediated DDAH gene transfer into the 5/6Nx rats prevented the elevation of BP levels, which was associated with the reduction of plasma and urinary ADMA levels. The results presented here suggest that decreased DDAH levels as well as increased PRMT gene expression could cause the elevation of plasma ADMA levels, thereby eliciting hypertension in CKD. Substitution of DDAH protein or enhancement of its activity may become a novel therapeutic strategy for the treatment of hypertension-related vascular injury in CKD.


Assuntos
Arginina/análogos & derivados , Hipertensão/fisiopatologia , Falência Renal Crônica/fisiopatologia , Adenoviridae/genética , Amidoidrolases/metabolismo , Animais , Arginina/biossíntese , Arginina/sangue , Arginina/farmacocinética , Arginina/urina , Colesterol/sangue , Hipertensão/complicações , Rim/enzimologia , Falência Renal Crônica/complicações , Cinética , Fígado/enzimologia , Masculino , Nefrectomia , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA