Numerical Study on the Effect from Nitric Oxide on Regulation of Pulmonary Vascular in Different Pulmonary Ventilation Conditions / 医用生物力学

ABSTRACT

Objective To study the changes of nitric oxide (NO) concentration in arterial-capillary-venous vessels and the dynamic regulation mechanism of NO on the vessels during ventilation changes. Method The pulmonary vascular network model was established by using the COMSOL Multiphysics software, the dynamic regulation of NO on blood vessels was introduced, the flow-multiphysics coupling simulation was conducted to explore the effect of oxygen and blood flow on NO concentration and its distribution in pulmonary vascular network, and the dynamic regulation of NO on pulmonary vascular function in the case of ventilation lacking. Results Oxygen concentration and blood flow would jointly affect the NO distribution in the pulmonary vascular network. When lung ventilation was insufficient, the amount of oxygen entering the pulmonary capillaries decreased, and the NO concentration in pulmonary vein walls under static conditions was significantly reduced. The reduction of NO concentration under dynamic conditions led to vasoconstriction and decrease of blood vessel radius, resulting a dynamic compensation. Regulation of vascular tension regulation coefficient α would directly affect the regulation of NO. When α worked within a certain range, a higher value of α meant a larger change in vascular radius and a smaller change in NO concentration, and its effective value was greater than 1. Conclusions The research findings revealed the change of NO concentration in arterial-capillary-venous vessels due to the change of ventilation as well as the dynamic regulation mechanism of NO in blood vessels, and predicted the effective value range of α，thus providing theoretical basis for further research on the mechanism of blood flow, ventilation perfusion ratio affected by vasoconstriction and vascular resistance changes due to ventilation insufficiency.