Peroxisome proliferator-activated receptor alpha and alpha/gamma agonists do not cause impairment in renal function in the rat.

Background/aims: Patients treated with peroxisome proliferator-activated receptor analogs (PPAR) alpha or alpha/gamma may develop a transient and reversible increase in serum creatinine, the mechanism of which remains obscure. This study evaluates whether treatment with either PPAR-alpha or -alpha/gamma analogs, fenofibrate or tesaglitazar, may cause deterioration in renal hemodynamics or exert direct tubular or glomerular nephrotoxic effects in rats.

Methods: Male Sprague-Dawley rats (300-320 g) were treated per os with fenofibrate (300 mg/kg/day), tesaglitazar (1.2 mg/kg/day) or vehicle, for 14 days. Glomerular filtration rate (GFR) and renal blood flow (RBF) were measured by inulin clearance and ultrasonic flowmetry, and cumulative excretion of sodium and creatinine were assessed. Biomarkers of glomerular and tubular injury were measured, including urinary albumin excretion and renal mRNA levels of kidney injury molecule 1 (Kim-1), lipocalin 2 (Lcn2), and osteopontin (Spp1).

Results: Fenofibrate and tesaglitazar improved the lipid profile, but caused no detectable decrease in GFR or RBF compared with vehicle-treated rats. Furthermore, the cumulative excretions of sodium and creatinine were not altered by the drugs. Finally, there was no significant difference between drug- and vehicle-treated groups in urinary albumin excretion or in the expression of renal injury biomarkers.

Conclusions: In the rat, no direct nephrotoxic effect or deterioration in renal hemodynamics and function were observed following treatment with fenofibrate or tesaglitazar.