Colfibrate attenuates blood pressure and sodium retention in DOCA-salt hypertension

Clofibrate, a peroxisome proliferator-activated receptor-α (PPARα) agonist, increases renal tubular cytochrome P450 4a (Cyp4a) expression thereby increasing 20-hydroxyeicosatetraenoic acid (20-HETE) production. To determine if clofibrate affects blood pressure regulation we studied mice with DOCA-salt induced hypertension in wild-type and PPARα knockout mice. Wild-type mice treated with DOCA-salt had higher mean arterial pressures and higher cumulative sodium balance, but lower renal 20-HETE production than did vehicle-treated mice. Treating DOCA-salt mice with clofibrate attenuated the increase in mean arterial pressure and cumulative sodium balance while increasing 20-HETE production and renal Cyp4a expression. In contrast the PPARα knockout mice treated with clofibrate and DOCA-salt showed no attenuation in the increase of blood pressure, cumulative sodium balance, renal 20-HETE production or Cyp4a protein expression. Expression of the PPARα protein was greater in proximal tubules than in renal microvessels. Our results show that PPARα pathway induces renal tubular 20-HETE production which affects sodium retention and blood pressure regulation in DOCA-salt-treated mice.