Just to give a quick intro, I am working on HMEC-1 cells (microvascular endothelial cells). I am not having a problem getting a giga ohm seal and going whole cell. I have however, noticed my seal resistance slowly decreases with time, together with this decrease, my currents also increase. I realize this maybe explained by Ohm's Law increasing currents causes decreasing resistance. The seal resistance increases with a bath solution containing NPPB (a chloride channel blocker) the currents also decrease. The currents in my cells are mainly chloride from what I believe, change in bath potassium and sodium have very little change in the membrane potential or reversal potential.
I am worried that the currents are artificial and only increasing due to the drop in seal resistance but I maybe incorrect and the increasing currents are physiological in which case the decreasing seal resistance is not an issue.
Please can someone shed some light on this?
Thank you for your time to help