A formulation for vasomotion and vessel myogenic response written in collaboration with Bard Ermentrout, University of Pittsburgh, has been completed. It incorporates smooth muscle ionic transports-calcium and potassium-and the associated electrical and contraction of a thick walled cylinder of small artery dimensions. The model reproduces the experimental responses to changes in intraluminal pressure (myogenic property). The analysis is contained in the paper """"""""On the Origin and Dynamics of the Vasomotion of Small Arteries,"""""""" Mathematical Biosciences, in press. The formulation is being extended with the purpose of incorporating several aspects of the microcirculatory control: mechanical, neuro- humoral and metabolic. The rheological effects of the vasomotion on a microcirculatory network has been modeled. For some sets of rheological parameters, synchronization of the different arterioles is obtained; this suggests a mechanism for the similar phenomenon observed in sickle cell disease (with Bard Ermentrout, University of Pittsburgh). To study the behaviors associated with neuro-humoral controls (posture, hypertension), we have started to model agonists modulation of vasomotion and tone mediated by G-protein associated second messenger (with Daniel Goldstein, University of Buenos Aires, School of Sciences). We have developed a model that associates changes in tissue ADP/ATP with L-type Ca-channels and K ATP-sensitive channels activities. Different metabolic demands are shown to be associated with different vasomotion patterns. A feature of interest is that the classical """"""""capillary recruitment"""""""" is replaced by an """"""""ensemble phase coincidence"""""""".
