Renal dopamine receptors have been shown to play a critical role in ROS-dependent hypertension. D5 dopamine receptor deficient (D5-/-) mice are hypertensive and have increased systemic oxidative stress which is manifested in the kidney and the brain. To further investigate the Underlying mechanisms of hypertension in D5-/- mice, we used RNA arrays to compare mRNA levels of kidneys from wildtype and D5-/- mice. Our data show, that the mRNA level of alpha/beta hydrolase 1 (ABHD1) is significantly upregulated in D5-/- mice. Additionally, overexpression of ABHD1 in a new established renal proximal tubule cell line reduced the amount of O-2(-) produced by the NADPH oxidase. Therefore the upregulation of ABHD1 in D5-/- mice Could be an answer to the increased oxidative stress. While oxidative stress is an important factor For the development of hypertension, ABHD I could play a protective role in the pathogenesis of hypertension. (C) 2008 Elsevier Inc. All rights reserved.