BIOMECHANICAL MODEL FOR THE MYOGENIC RESPONSE IN THE MICROCIRCULATION.1. FORMULATION AND INITIAL TESTING

The pressure dependent or myogenic contraction of arterioles is one of the most fundamental control mechanisms of microvascular perfusion. W hile many experimental observations have been obtained on the myogenic response, no generally accepted biomechanical model has been formulat ed. A novel biomechanical theory is proposed based on two fundamental assumptions: the arteriolar wall exhibits viscoelastic properties befo re and during myogenic contractions, and the contraction is achieved b y a pressure dependent change of reference length. The formulation of the model and its application to different experimental procedures on microvascular smooth muscle in the literature is presented. The model describes closely a broad spectrum of steady and unsteady pressure dep endent diameter variations of arterioles under a pressure dependent st imulus.