Calcium Spots

Abstract

Blood flow-mediated mechanical force, ie, shear stress, plays an important role in regulation of vascular function and development of various cardiovascular diseases. [1][2][3] It directly stimulates vascular endothelial cells to mobilize intracellular Ca 2ϩ ([Ca 2ϩ ] i ), resulting in production of endothelium-derived vasoactive substances, such as nitric oxide and prostacyclin, which cause vasodilation by acting on smooth muscle cells. [1][2][3] In this process, the mechanosensitive (MS) channel is an important pathway mediating the shear stress-induced increase in [Ca 2ϩ ] i . 4 -7 In addition, a specific vasoactive agonist, ATP, has been regarded as an important shear transducer of the endothelial [Ca 2ϩ ] i mobilization in response to fluid flow. spots and the corresponding activation of MS channels was not assessed in this study, no direct evidence was provided to indicate that the Ca 2ϩ spots are an elementary phenomenon. However, it is reasonable to consider that they are an elementary phenomenon, based on the observation that the The opinions expressed in this editorial are not necessarily those of the editors or of the American Heart Association.

Nitric Oxide Signaling in the Microcirculation

“…20,21 Typical [Ca 2+ ] i responses following step changes in shear stress were recently reported for bovine aortic ECs by Hong et al 22 Fluorescence imaging shows a synchronous response with higher average peak amplitude at higher shear stresses (Fig. 1A), with similar rapid time courses for individual measurements (Fig.…”