Abstract
We have studied the effect of intracellular ATP on volume-activated Cl−-currents in endothelial cells from human umbilical veins by means of the whole-cell patch clamp technique. The run-down of this current in ruptured patches during repetitive applications of hypotonic solutions (HTS) could be significantly reduced if the cells were internally perfused with a pipette solution that contained 4 mmol/l ATP. This run-down was much less pronounced if currents were recorded using nystatin-perforated patches. The amplitude of the current was drastically reduced and its activation became slower if the cells were superfused with a glucose-free medium with 1 mmol/l KCN. Adding 4 mmol/l ATPγS, a poorly hydrolyzable ATP-analogue, to the patch pipette prevented run-down of the current during repetitive activations by HTS, even if the cells were superfused with glucose-free solution with 1 mmol/l KCN. It is concluded that activation of the mechanosensitive Cl− conductance in human endothelial cells requires the presence of intracellular ATP, but not its hydrolysis.
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Oike, M., Droogmans, G. & Nilius, B. The volume-activated chloride current in human endothelial cells depends on intracellular ATP. Pflügers Arch. 427, 184–186 (1994). https://doi.org/10.1007/BF00585960
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DOI: https://doi.org/10.1007/BF00585960