Hypothalamic paraventricular nucleus (PVN) and rostral ventrolateral medulla (RVLM) play an important role in brain control of blood pressure (BP). One of the important mechanisms involved in the pathogenesis of hypertension is the elevation of reactive oxygen species (ROS) production by nicotine adenine dinucleotide phosphate (NADPH) oxidase. The aim of our present study was to investigate NADPH oxidase -mediated superoxide (O 2 - ) production and to search for the signs of lipid peroxidation in hypothalamus and medulla oblongata as well as in renal medulla and cortex of hypertensive male rats transgenic for the murine Ren -2 renin gene (Ren -2 TGR) and their age -matched normotensive controls ‒ Hannover Sprague Dawley rats (HanSD) . We found no difference in the activity of NADPH oxidase measured as a lucigenin -mediated O 2 - production in the hypothalamus and medulla oblongata. However, we observed significantly elevated NADPH oxidase in both renal cortex and medulla of Ren -2 TGR com pared with HanSD. Losartan (LOS) treatment (10 mg/kg body weight/day) for 2 months (Ren -2 TGR+LOS) did not change NADPH oxidase -dependent O 2 - production in the kidney. We detected significantly elevated indirect m arkers of lipid peroxidation measured as th iobarbituric acid -reactive substance s (TBARS) in Ren -2 TGR, while they were significantly decreased in Ren -2 TGR +LOS. In conclusion, the present study shows increased NADPH oxidase activities in renal cortex and medulla with significantly increased TBARS in renal cortex. No significant changes of NADPH oxidase and markers of lipid peroxidation were detected in the studied brain regions., M. Vokurková, H. Rauchová, L. Řezáčová, I. Vaněčková, J. Zicha., and Obsahuje bibliografii
Enhanced production of superoxide radicals by nicotinamideadenine dinucleotide phosphate (NADPH) oxidase in the brain and/or kidney of salt hypertensive Dahl rats has been proposed to participate in the pathogenesis of this form of experimental hypertension. Most information was obtained in young Dahl saltsensitive (DS) rats subjected to high salt intake prior to sexual maturation. Therefore, the aim of our study was to investigate whether salt hypertension induced in adult DS rats is also accompanied with a more pronounced oxidative stress in the brain or kidney as compared to Dahl salt-resistant (DR) controls. NADPH oxidase activity as well as the content of thiobarbituric acid-reactive substances (TBARS) and conjugated dienes (oxidative index), which indicate a degree of lipid peroxidation, were evaluated in two brain regions (containing either hypothalamic paraventricular nucleus or rostral ventrolateral medulla) as well as in renal medulla and cortex. High salt intake induced hypertension in DS rats but did not modify blood pressure in DR rats. DS and DR rats did not differ in NADPH oxidase-dependent production of ROS, TBARS content or oxidative index in either part of the brain. In addition, high-salt diet did not change significantly any of these brain parameters. In contrast, the enhanced NADPH oxidase-mediated ROS production (without significant signs of increased lipid peroxidation) was detected in the renal medulla of salt hypertensive DS rats. Our findings suggest that there are no signs of enhanced oxidative stress in the brain of adult Dahl rats with salt hypertension induced in adulthood., M. Vokurková, H. Rauchová, L. Řezáčová, I. Vaněčková, J. Zicha., and Obsahuje bibliografii