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

Clofibrate, a peroxisome proliferator-activated receptor-alpha (PPAR alpha) 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 PPAR alpha 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 PPAR alpha 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 PPAR alpha protein was greater in proximal tubules than in renal microvessels. Our results show that PPARa pathway induces renal tubular 20-HETE production which affects sodium retention and blood pressure regulation in DOCA- salt-treated mice.