A mechanosensitive cation channel in endothelial cells and its role in vasoregulation

Abstract

Ca²⁺ is an important intracellular second messenger in signal transduction of endothelial cells. It has long been recognized that a mechanosensitive Ca²⁺‐permeable channel is present in vascular endothelial cells. The activity of this channel may increase intracellular Ca²⁺ level in endothelial cells. A recent finding is that the activity of this channel may be regulated by cGMP through a protein kinase G‐dependent pathway. Inhibition of the channel by cGMP abolishes the Ca²⁺ influx elicited by flow. Several inhibitors of the cation channel including Gd³⁺, Ni²⁺, and SK&F‐96365 also inhibit the Ca²⁺ influx due to flow stimulation. These data suggest that a mechanosensitive cation channel is the primary pathway mediating the flow‐induced Ca²⁺ entry in vascular endothelial cells. Another important finding is that the opening of this mechanosensitive channel by KT5823 leads to endothelium‐dependent vascular dilation. Therefore, it appears that this channel may play a crucial role in the regulation of vascular tone.