Role of cytochrome P-450 metabolites in the regulation of renal function and blood pressure in 2-kidney 1-clip hypertensive rats

Am J Physiol Regul Integr Comp Physiol. 2011 Jun;300(6):R1468-75. doi: 10.1152/ajpregu.00215.2010. Epub 2011 Mar 16.

Abstract

Alterations in renal function contribute to Goldblatt two-kidney, one-clip (2K1C) hypertension. A previous study indicated that bioavailability of cytochrome P-450 metabolites epoxyeicosatrienoic acids (EETs) is decreased while that of 20-hydroxyeicosatetraenoic acids (20-HETE) is increased in this model. We utilized the inhibitor of soluble epoxide hydrolase cis-4-[4-(3-adamantan-1-yl-ureido)-cyclohexyloxy]-benzoic acid (c-AUCB) and HET-0016, the inhibitor of 20-HETE production, to study the role of EETs and 20-HETE in the regulation of renal function. Chronic c-AUCB treatment significantly decreased systolic blood pressure (SBP) (133 ± 1 vs. 163 ± 3 mmHg) and increased sodium excretion (1.23 ± 0.10 vs. 0.59 ± 0.03 mmol/day) in 2K1C rats. HET-0016 did not affect SBP and sodium excretion. In acute experiments, renal blood flow (RBF) was decreased in 2K1C rats (5.0 ± 0.2 vs. 6.9 ± 0.2 ml·min(-1)·g(-1)). c-AUCB normalized RBF in 2K1C rats (6.5 ± 0.6 ml·min(-1)·g(-1)). HET-0016 also increased RBF in 2K1C rats (5.8 ± 0.2 ml·min(-1)·g(-1)). Although RBF and glomerular filtration rate (GFR) remained stable in normotensive rats during renal arterial pressure (RAP) reductions, both were significantly reduced at 100 mmHg RAP in 2K1C rats. c-AUCB did not improve autoregulation but increased RBF at all RAPs and shifted the pressure-natriuresis curve to the left. HET-0016-treated 2K1C rats exhibited impaired autoregulation of RBF and GFR. Our data indicate that c-AUCB displays antihypertensive properties in 2K1C hypertension that are mediated by an improvement of RBF and pressure natriuresis. While HET-0016 enhanced RBF, its anti-natriuretic effect likely prevented it from producing a blood pressure-lowering effect in the 2K1C model.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amidines / pharmacology
  • Animals
  • Arachidonic Acids / metabolism
  • Blood Pressure / drug effects
  • Blood Pressure / physiology*
  • Cytochrome P-450 Enzyme System / metabolism*
  • Disease Models, Animal
  • Enzyme Inhibitors / pharmacology
  • Epoxide Hydrolases / antagonists & inhibitors
  • Hydroxyeicosatetraenoic Acids / metabolism
  • Hypertension, Renovascular / metabolism*
  • Hypertension, Renovascular / physiopathology*
  • Kidney / blood supply
  • Kidney / drug effects
  • Kidney / physiology*
  • Male
  • Rats
  • Regional Blood Flow / drug effects
  • Sodium / urine

Substances

  • Amidines
  • Arachidonic Acids
  • Enzyme Inhibitors
  • HET0016
  • Hydroxyeicosatetraenoic Acids
  • 20-hydroxy-5,8,11,14-eicosatetraenoic acid
  • Cytochrome P-450 Enzyme System
  • Sodium
  • Epoxide Hydrolases