RESUMO
OBJECTIVE: To determine whether angiotensin converting enzyme inhibition by perindopril can reduce cardiac transforming growth factor beta1 (TGFbeta1) and plasminogen activator inhibitor 1 (PAI-1) and therefore control collagen accumulation in an animal model with the metabolic syndrome such as the obese Zucker rat (OZR). ANIMALS: Male OZR (group 1, n = 10); OZR treated with perindopril (group 2, n = 10); and lean Zucker rats (group 3, n = 10). METHODS: During six months, group 2 received 3 mg/kg/day of perindopril orally and group 1 and group 3 were given a vehicle. Hearts were processed for pathology studies including immunohistochemical analysis with antibodies to PAI-1, TGFbeta1, collagen type I, and collagen type III. RESULTS: Group 2 had lower blood pressure (126.7 (2) v 148.6 (2.7) mm Hg, p < 0.01) than untreated OZR and had decreased cardiac PAI-1 (3.6 (0.4) v 13.5 (1.7)% of positive area/field, p < 0.01), TGFbeta1 in myocytes (0.13 (0.1) v 9.14 (4.7)%/area, p < 0.01) and in interstitium (19.8 (6.8) v 178.9 (27.4) positive cells/area, p < 0.01), collagen I (3 (0.8) v 13.3 (1)%/area, p < 0.01), collagen III (5 (0.6) v 9.5 (0.9)%/area, p < 0.01), and collagen I to collagen III ratio (0.59 (0.13) v 1.40 (0.15) p < 0.01) compared with untreated OZR. CONCLUSION: These results suggest that perindopril reduces cardiac PAI-1 and TGFbeta1 and ameliorates cardiac fibrosis in a rat model with multiple cardiovascular risk factors.
Assuntos
Inibidores da Enzima Conversora de Angiotensina/farmacologia , Síndrome Metabólica/metabolismo , Perindopril/farmacologia , Inibidor 1 de Ativador de Plasminogênio/metabolismo , Fator de Crescimento Transformador beta/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Colágeno/metabolismo , Modelos Animais de Doenças , Masculino , Síndrome Metabólica/patologia , Miocárdio/metabolismo , Miocárdio/patologia , Obesidade/metabolismo , Obesidade/patologia , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Zucker , Fator de Crescimento Transformador beta/metabolismo , Fator de Crescimento Transformador beta1RESUMO
Although controversial, chronic uric acid nephropathy is a tubulointerstitial disease capable of developing renal function loss. On the other hand, potassium citrate (KCi) administration has demonstrated to be effective in calcium as well as uric acid nephrolithiasis therapy. Therefore, the aim of the present study was to evaluate the possible benefit of KCi treatment in the prevention or amelioration of renal interstitial damage in uric acid nephropathy. Two-month-old male Sprague-Dawley rats were divided into 3 groups: G1 hyperuricemic (HU), G2 hyperuricemic + KCi (HU+KCi), and G3 KCi. G1 and G2 were fed on oxonic acid (inhibitor of rat liver uricase), and a uric acid supplement, during 4 weeks. G2 and G3 were given 2% KCi in drinking water, and G1 regular tap water and standard rat chow. At the end of the study, renal tissue was processed for light and electron microscopy and immunostaining by alpha-smooth muscle actin (SMA). Tubulointerstitial lesions and the amount of alpha-SMA immunostaining in renal tissue were evaluated by histomorphometric quantitation. Rats belonging to the hyperuricemic groups treated with KCi (G2) showed fewer tubulointerstitial lesions as follows: % tubular atrophy: 1.7 +/- 0.3 versus 7.2 +/- 1.2, p < 0.05; inflammatory cells infiltrate (number of cells/area): 0.6 +/- 0.1 versus 2.4 +/- 0.2, p < 0.01; % interstitial fibrosis (cortex): 3.3 +/- 0.3 versus 9.3 +/- 0.5, p < 0.05; % interstitial fibrosis (medulla): 5.2 +/- 0.3 versus 21.9 +/- 1.2, p < 0.01, lower albuminuria (32.8 +/- 11.2 mg/day versus 128.5 +/- 10.4, p < 0.01), higher creatinine clearance ( 1.36 +/- 0.02 ml/min versus 0.74 +/- 0.01, p < 0.01 ) and less percentage of alpha-SMA in renal tissue (1.8 +/- 0.1 versus 10.5 +/- 1.4, p < 0.05), when compared with the hyperuricemic group not treated with KCi (G1). These data suggest that KCi administration could provide a substantial benefit in the regard to tubulointerstitial lesion and progressive renal damage.