The role of haem in smooth muscle cells

Haem regulation of arterial smooth muscle potassium channels

Blood pressure is maintained by the contraction of smooth muscle cells (in blood vessels called vasoconstriction) which in turn depends on an electrical difference being maintained between the inside and outside of vascular smooth muscle (the membrane potential). Potassium channels (K+ channels) are proteins in the membrane which have an important role in setting the membrane potential, and any change in their activity will alter both membrane potential and vasoconstriction. Haem is an important molecule involved in many reactions that occur inside cells and haem can alter the activity of K+ channels. Dr Noel Davies and his team at the University of Leicester will investigate the regulation of K+ channels in vascular smooth muscle by haem and the gases carbon dioxide and nitric oxide, which interact with haem. They hope to determine how the cell environment affects haem modulation. The results of this study should enable predictions to be made of how haem will regulate K+ channels and thereby alter contraction of smooth muscle. In the longer term, such knowledge has potential for the development of novel therapeutic strategies designed to tackle vascular disease.