Integration of non-linear cellular mechanisms regulating microvascular perfusion

It is becoming increasingly evident that interactions between the different cell types present in the vessel wall and the physical forces that result from blood flow are highly complex. This short article will review evidence that irregular fluctuations in vascular resistance are generated by non-li nearity in the control mechanisms intrinsic to the smooth muscle cell and c an be classified as chaotic. Non-linear systems theory has provided insight s into the mechanisms involved at the cellular level by allowing the identi fication of dominant control variables and the construction of one-dimensio nal iterative maps to model vascular dynamics. Experiments with novel pepti de inhibitors of gap junctions have shown that the coordination of aggregat e responses depends on direct intercellular communication. The sensitivity of chaotic trajectories to perturbation may nevertheless generate a high de gree of variability in the response to pharmacological interventions and al tered perfusion conditions.