A three-state non-linear model of vascular nitric oxide transport

Nitric oxide (NO) plays a crucial role in the regulation of blood flow around the body. Biological experiments have shown that blocking NO production induces vasomotion, which is caused by instabilities in blood vessel walls. It has been suggested that the observed vasomotion on NO blockade is because a NO flow dependent system is actually stabilised by the myogenic system, since the coupling together of two unstable mechanisms can enable a system to become stable. We thus propose here a model for the interaction between flow and NO production, with a flow feedback mechanism and analyse its stability both numerically and analytically. We show that the presence of flow feedback introduces instability, which thus provides the basis for a more detailed model of the autoregulation response, when coupled with a model of the myogenic response, and derive a result for the oscillation frequency of the system.