A mechanism of oxygen free radical production in the Dahl hypertensive rat

Citation
A. Swei et al., A mechanism of oxygen free radical production in the Dahl hypertensive rat, MICROCIRCUL, 6(3), 1999, pp. 179-187
Citations number
37
Categorie Soggetti
Cardiovascular & Hematology Research
Journal title
MICROCIRCULATION
ISSN journal
10739688 → ACNP
Volume
6
Issue
3
Year of publication
1999
Pages
179 - 187
Database
ISI
SICI code
1073-9688(199909)6:3<179:AMOOFR>2.0.ZU;2-N
Abstract
Objective: To determine if oxygen free radicals derived from xanthine oxida se are involved in the development of salt-induced hypertension. Enhanced p roduction of oxygen free radicals may play a role in hypertension by affect ing vascular smooth muscle contraction and provide a mechanism for lesion f ormation. Methods: Dahl salt-sensitive (Dahl-S) and salt-resistant (Dahl-R) rats mere fed either a low-salt, high-salt or high-salt + tungsten diet for 4 wk. In vivo production of superoxide (O-2(-)) was detected by the reduction of a tetranitroblue tetrazolium (TNBT) dye in the rat mesentery, while plasma hy drogen peroxide (H2O2) production levels mere determined using a modified e lectrochemical electrode technique. Results: The tungsten diet lowered the blood pressure of Dahl-S rats compar ed to high-salt-treated Dahl-S rats, but had no effect on blood pressure in Dahl-R rats. Light absorption of formazan deposits revealed that tungsten- treated Dahl-S rats had reduced TNBT staining along the endothelium of arte rioles and venules compared to hypertensive, high-salt-treated Dahl-S rats. In addition, tungsten-treated Dahl-S rats had a lower plasma H2O2 concentr ation compared to hypertensive, high-salt-treated Dahl-S rats. Conclusions: These findings indicate that xanthine oxidase-derived oxygen f ree radicals are involved in the pathogenesis of salt-induced hypertension.