MEMBRANE-FUNCTION AND VASCULAR REACTIVITY

This communication examines the possibility that nitric oxide (NO) pro duction by endothelial cells results from changes in cell membrane flu idity. Lysophosphatidylcholine (LPC) alters fluidity of the endothelia l cell membranes causing vascular relaxation. Through membrane alterat ions LPC influences function of a number of membrane receptors and mod ulates enzyme activity. As a result of detergent action, lysophosphati dylcholine (LPC) causes activation of guanylate cyclase, stimulates sy alytransferase and regulates protein kinase C activity. It has already been demonstrated that ionic detergents, such as Triton X-100 also ca use vascular relaxation, possibly induced by NO production from endoth elial cells. It is postulated that production of nitric oxide results from changes in membrane viscosity; this may represent a mechanism for its regulation in biological systems.