Phenylephrine,9 (link) ACh,9 (link) RN1734,7 (link) GSK1016790A,13 (link) NG-nitro-L-arginine (L-NNA),8 (link) indomethacin,8 (link) and apamin8 (link) were purchased from Sigma-Aldrich (St. Louis, MO, USA). Anti-KCa2.3 (catalog No. APC-025) and anti-TRPV4 (catalog No. ACC-034) antibodies were purchased from Alomone Labs.