Activation of cardiac connexin 43 hemichannels by shear stress and subsequent contribution of pannexins in left-side cardiac myocytes

Abstract

Cardiac myocytes are exposed to shear stress under physiological conditions and hemodynamic disturbances. Shear stress has been thought to trigger global Ca2+ waves in atrial myocytes through autocrine activation of P2 receptors by connexin43 (Cx43)-mediated ATP release. We examined whether shear stress activates Cx43 hemichannels and pannexins in atrial and ventricular myocytes from right and left side of heart chambers. The activities of these hemichannels were measured as an efflux of large fluorescence dye (calcein-red/orange) to permeate these channels using two-dimensional confocal imaging method in single isolated myocytes of murine hearts.