Impact of androgen-induced oxidative stress on hypertension in male SHR

Am J Physiol Regul Integr Comp Physiol. 2007 Feb;292(2):R731-5. doi: 10.1152/ajpregu.00353.2006. Epub 2006 Jul 20.

Abstract

Men have higher blood pressure than women, and androgens and oxidative stress have been implicated as playing roles in this sexual dimorphism. The spontaneously hypertensive rat (SHR) is an animal model of both androgen- and oxidative stress-mediated hypertension. Therefore, the present studies were performed to test the hypothesis that androgens cause hypertension in SHR in part by stimulating superoxide production via NADPH oxidase. Castration of male SHR reduced blood pressure by 15% and attenuated both basal and NADPH-stimulated superoxide production in kidney cortical homogenates. Expression of p47(phox) and gp91(phox) but not p22(phox) subunits of NADPH oxidase were significantly lower in kidney cortex from castrated males compared with intact males. Moreover, inhibition of NADPH oxidase with apocynin caused approximately 15 mmHg reduction in blood pressure and reduced basal and NADPH-stimulated superoxide production in intact male SHR, but had no effect on blood pressure or superoxide production in castrated males. These data support the hypothesis that androgens cause oxidative stress and thereby increase blood pressure in male SHR via an NADPH oxidase-dependent mechanism.

Publication types

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

MeSH terms

  • Acetophenones / pharmacology
  • Acridines / metabolism
  • Androgens / pharmacology*
  • Animals
  • Blood Pressure / drug effects
  • Body Weight / drug effects
  • Enzyme Inhibitors / pharmacology
  • Hypertension / physiopathology*
  • Kidney / metabolism
  • Kidney Cortex / enzymology
  • Luminescence
  • Male
  • NADPH Oxidases / antagonists & inhibitors
  • NADPH Oxidases / metabolism
  • Orchiectomy
  • Oxidative Stress / physiology*
  • Rats
  • Rats, Inbred SHR
  • Superoxides / metabolism

Substances

  • Acetophenones
  • Acridines
  • Androgens
  • Enzyme Inhibitors
  • Superoxides
  • 10,10'-dimethyl-9,9'-biacridinium
  • acetovanillone
  • NADPH Oxidases