Nitric Oxide Diffusion Rate is Reduced in the Aortic Wall

ABSTRACT

Endogenous nitric oxide (NO) plays important physiological roles in the body. As a small diatomic molecule, NO has been assumed to freely diffuse in tissues with a diffusion rate similar to that in water. However, this assumption has not been tested experimentally. In this study, a modified Clark-type NO electrode attached with a customized aorta holder was used to directly measure the flux of NO diffusion across the aortic wall at 37�C. Experiments were carefully designed for accurate measurements of the apparent NO diffusion coefficient D and the partition coefficient α in the aortic wall. A mathematical model was presented for analyzing experimental data. It was …