Nox inhibition in isolated rat mesenteric arteries via plasmid electroporation

Collateral growth (CG) is impaired with age. Previously, we have demonstrated that antioxidants, including a NAD(P)H oxidase (Nox) inhibitor, can reverse age‐related impairment in both flow‐mediated nitric oxide (NO) production and CG. The goal of the present study was to determine the optimal conditions for electroporation‐mediated delivery of siRNA to suppress Nox expression in rat mesenteric arteries. A plasmid containing shRNA to the Nox subunit p22 phox , along with GFP DNA, was delivered into the arterial wall via square wave electroporation. We have designed a 4mm wide electroporation chamber to allow for both isolated fragment and in vivo electroporation of a 10–15 mm long mesenteric vascular bundle with minimal vector volume and mesenteric tissue manipulation. The results show optimal electroporation conditions of isolated vessels at 125V (312.5V/cm) with 8 pulses of 10msec duration as shown by comparative GFP fluorescence at 48hrs post electroporation. Superoxide production was assessed by monitoring DHE staining of the vessel fragments. Future studies will be focused on optimizing in vivo electroporation conditions and determining the Nox isoforms responsible for the observed flow‐mediated impaired collateral response. Sponsored by NIH HL092012‐S1.