Mechanically Induced Calcium Mobilization in Cultured Endothelial Cells isDependent on Actin and Phospholipase

摘要

We sought to evaluate the mechanisms by which mechanical perturbation elevatesintracellular calcium in endothelial cells. We report that the transient elevation in intracellular calcium in cultured bovine aortic endothelial cells (BAEC) in response to gentle perturbation with the side of a micropipette was not blocked by depolarization. Thus, voltage-dependent calcium channels were not involved in the response. Also, amiloride (10 i%mol/L) and tetraethylammonium (1 mmol/L) had no effect on calcium mobilization, indicating that Na+ and K+ transporters were not involved. Pretreatment of the cells with the phospholipase C and phospholipase A2 inhibitor manoalide for 10 minutes at 37%C completely abolished the calcium response, as did a 10-minute pretreatment with the inhibitor of actin polymerization, cytochalasin B (1 ,imol/L). We observed an inhibitory effect of the phospholipase A2 and phospholipase C inhibitor 4-bromophenacyl bromide (10 %mol/L) on the mechanical response of BAEC that was not as potent as that observed with manoalide.