Vasoconstriction resulting from dynamic membrane trafficking of TRPM4 in vascular smooth muscle cells.

The melastatin (M) transient receptor potential (TRP) channel TRPM4 mediates pressure and protein kinase C (PKC)-induced smooth muscle cell depolarization and vasoconstriction of cerebral arteries. We hypothesized that PKC causes vasoconstriction by stimulating translocation of TRPM4 to the plasma membrane. Live-cell confocal imaging and fluorescence recovery after photobleaching (FRAP) analysis was performed using a green fluorescent protein (GFP)-tagged TRPM4 (TRPM4-GFP) construct expressed in A7r5 cells.

Endothelium-dependent cerebral artery dilation mediated by TRPA1 and Ca2+-Activated K+ channels.

Although it is well established that changes in endothelial intracellular [Ca(2+)] regulate endothelium-dependent vasodilatory pathways, the molecular identities of the ion channels responsible for Ca(2+) influx in these cells are not clearly defined. The sole member of the ankyrin (A) transient receptor potential (TRP) subfamily, TRPA1, is a Ca(2+)-permeable nonselective cation channel activated by electrophilic compounds such as acrolein (tear gas), allicin (garlic), and allyl isothiocyanate (AITC) (mustard oil). The present study examines the hypothesis that Ca(2+) influx via TRPA1 causes endothelium-dependent vasodilation.