Signal Transduction in Endothelium: Mechano-Sensing, Ion Channels and Intracellular Calcium

To all endothelial electrophysiologists

I've been working for long with cultured endocardial endothelial cells, in which I never observed spontaneous transient outward or inward currents (STOC's or STIC's). On the other hand, in freshly isolated aortic endothelial cells, about 30% of the cells displayed STOC's or STIC's (depending on holding potential), which were not accompanied by calcium signals (Fransen, Katnik and Adams, AJP, 1998). Are STOC's and STIC's typical for fresh cells (They have a rounded shape, while cultured cells are flat with many protrudings)? Do fresh cells have different calcium signals? do they have a different organization of the SR (ryanodine- and/or IP3-sensitive compartments)and if so, this might be important for calcium signalling and release of endothelium-derived factors.

Thu Dec 10