Urinary cytokine profiles according to the site of blockade of the renin-angiotensin system in nephrectomized rats.

INTRODUCTION

It is still unknown how the pharmacological inhibition of the Renin Angiotensin System (RAS) impacts the levels of inflammation and fibrosis biomarkers.

OBJECTIVE

This study sought to evaluate the effect of enalapril, candesartan and aliskiren on urinary levels of cytokines in a model of chronic kidney disease (CKD).

METHODS

Male Wistar rats were submitted to surgical removal of ¾ of renal parenchyma to induce CKD (¾ nephrectomy), or subjected to sham surgery (control). Animals were then randomized into five groups: Sham surgery receiving vehicle; ¾ Nephrectomy receiving vehicle; ¾ Nephrectomy receiving enalapril (10 mg/kg); ¾ Nephrectomy receiving candesartan (10 mg/kg) and ¾ Nephrectomy receiving aliskiren (10 mg/kg). Urine output, water intake, mean arterial pressure (MAP) and urinary concentrations of creatinine, urea, albuminuria, Na+, K+, interleukin (IL) -1β, IL-6, IL-10 and transforming growth factor beta (TGF-β) were measured.

RESULTS

Nephrectomy significantly impaired renal function, increased MAP and altered the levels of all evaluated cytokines in urine. Enalapril, candesartan and aliskiren improved renal function and decreased MAP and IL-6 when compared to vehicle-treated nephrectomized group. Candesartan and aliskiren decreased IL-1β, while only candesartan reduced TGF-β and only aliskiren increased IL-10.

CONCLUSION

Enalapril, candesartan and aliskiren presented similar effects on improving renal function and reducing MAP and urinary levels of IL-6 in rats with CKD. On the other hand, cytokine profile differed according to the treatment, suggesting that differential mechanisms were triggered in response to the site of RAS blockade.