Dopamine Receptor And Raft Lipids Regulate NADPH Oxidase Activity In Hypertensive Renal Proximal Tubule Cells

Objective Investigate the expression and activity of NADPH oxidase (Nox) subunit in hypertensive renal proximal tubule cells (HT) and the regulatory roleof dopamine receptors and lipid boat. Methods Cells were seprated into normotensivegroup(NT) and hypertensive group (HT), Dopamine receptor agonist of fenoldopam aswell as cholesterol depleting agent βCD were used to stimulate HT and NT,glucoseconcentration gradient to extract cell membrane lipid rafts and non-lipid rafts region,the expression levels of Nox subunits were detected by Western blot, NADPH oxidaseactivity were measured by Lucigenin Chemiluminescence. Results Dopamine receptoragonist of fenoldopam significantly reduced gp91expression in membrane lipid raftregions both in NT［（17±3.3）%］ and in HT［（20±3.4）%, P <0.05, n=4］, alsoreduced p22［（15±2.0）%, P <0.05, n=3］, p67, rac1expression in lipid rafts in NT,but didn’t reduce the p22, p67, rac1protein expression in HT; Cholesterol depletingagent βCD reduced gp91,p22expression in lipid rafts in NT, but didn’t reduce noxexpression in the area of lipid rafts of hypertension group; The basic Nox activity was4-fold higher in HT than in NT. Conclusion Nox subunits expressions are higher inHT than in NT, the regulations of dopamine receptor and lipid rafts on Nox subunitexpressions are weakened.