URINARY TRANSFORMING-GROWTH-FACTOR-BETA (TGF-BETA) EXCRETION AND RENAL PRODUCTION OF TGF-BETA IN RATS WITH SUBTOTAL RENAL ABLATION - EFFECTOF ENALAPRIL AND NIFEDIPINE

The aim of the present study was to investigate the effect of enalapri l and nifedipine on renal transforming growth factor-beta (TGF-beta) p roduction and on the rate of urinary TGF-beta excretion in rats with s ubtotal renal ablation. After subtotal nephrectomy some animals were t reated with enalapril or nifedipine, Renal cortical TGF-beta mRNA leve ls were 68% higher in untreated nephrectomized rats (p < 0.05) and 39% higher in rats treated with nifedipine (p < 0.05) compared with contr ols, There was no difference in renal cortical TGF-beta mRNA content b etween the nephrectomized rats treated with enalapril and sham animals , showing that enalapril treatment prevented the increase of TGF-beta mRNA in nephrectomized rats. The rate of urinary TGF-beta excretion wa s 2.2 +/- 0.8 pg/min in sham animals, 61.5 +/- 40.1 pg/min in untreate d nephrectomized rats, 9.6 +/- 4.2 pg/min in nephrectomized rats treat ed with enalapril, and 55.2 +/- 24.46 pg/min in rats treated with nife dipine. The immunohistochemical reaction for TGF-beta in the renal cor tex was less intense in the nephrectomized rats treated with enalapril than in the other groups of rats with subtotal renal ablation. These data show that enalapril induces a decrease in renal TGF-beta producti on and in urinary TGF-beta excretion in rats with subtotal renal ablat ion, an effect associated with the protective action of this treatment on renal structure and function and suggest that the determination of the rate of urinary TGF-beta could be a useful procedure for the eval uation of disease progression and therapeutic efficacy in the remnant kidney model.