Fulvene-5 inhibition of Nadph oxidases attenuate activation of epitehlial sodium channels in A6 distal nephron cells.

Fulvene-5 inhibition of Nadph oxidases attenuate activation of epitehlial sodium channels in A6 distal nephron cells. Am J Physiol Renal Physiol. 2013 Jul 17; Authors: Trac D, Liu BC, Pao AC, Thomas SV, Park M, Downs CA, Ma HP, Helms MN Abstract Nadph oxidase 4 is an important cellular source of reactive oxygen species (ROS) generation in the kidney. Novel anti-oxidant drugs, such as Nox4-inhibitor compounds, are being developed. There is however, very little experimental evidence for the biological role and regulation of Nadph oxidase isoforms in the kidney. Herein, we show that Fulvene-5 is an effective inhibitor of Nox-generated ROS and report the role of Nox isoforms in activating epithelial sodium channels (ENaC) in A6 distal nephron cells via oxidant signaling and cell stretch activation. Using single channel patch clamp analysis, we report that Fulvene-5 blocked the increase in ENaC activity that is typically observed with H2O2 treatment of A6 cells: average ENaC NPo values decreased from a baseline level of 1.04±0.18 (mean±SE) to 0.25±0.08 following Fulvene-5 treatment. H2O2 treatment failed to increase ENaC activity in the presence of Fulvene-5. Moreover, Fulvene-5 treatment of A6 cells blocked the osmotic-cell stretch response of A6 cells; indicating that stretch activation of Nox-derived ROS plays an important role in ENaC regulation. Together, these findings indicate that Fulvene-5, and perhaps other classes of antioxidant inhib...
Source: Am J Physiol Renal P... - Category: Urology & Nephrology Authors: Tags: Am J Physiol Renal Physiol Source Type: research