Abstract.
The present study explored regulation of electrogenic ion transport across cultured mouse endometrial epithelium by extracellular ATP using the short-circuit current (I SC ) and the patch-clamp techniques. The cultured endometrial monolayers responded to apical application of ATP with an increase in I SC in a concentration-dependent manner (EC50 at 3 μm). Replacement of Cl− in the bathing solution or treatment of the cells with Cl− channel blockers, DIDS and DPC, markedly reduced the I SC , indicating that a substantial portion of the ATP-activated I SC was Cl−-dependent. Amiloride at a concentration (10 μm) known to block Na+ channels was found to have no effect on the ATP-activated I SC excluding the involvement of Na+ absorption. Adenosine was found to have little effect on the I SC excluding the involvement of P1 receptors. The effect of UTP, a potent P2U receptor agonist on the I SC was similar to that of ATP while potent P2X agonist, α-β-Methylene adenosine 5′-triphosphate (α-β-M-ATP) and P2Y agonist, 2-methylthio-adenosine triphosphate (2-M-ATP), were found to be ineffective. The effect of ATP on I SC was mimicked by the Ca2+ ionophore, ionomycin, indicating a role of intracellular Ca2+ in mediating the ATP response. Confocal microscopic study also demonstrated a rise in intracellular Ca2+ upon stimulation by extracellular ATP. In voltage-clamped endometrial epithelial cells, ATP elicited a whole-cell Cl− current which exhibited outward rectification and delayed activation and inactivation at depolarizing and hyperpolarizing voltages, respectively. The results of the present study demonstrate the presence of a regulatory mechanism involving extracellular ATP and P2U purinoceptors for endometrial Cl− secretion.
Article PDF
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Chan, H., Liu, C., Fong, S. et al. Regulation of Cl− Secretion by Extracellular ATP in Cultured Mouse Endometrial Epithelium . J. Membrane Biol. 156 , 45 –52 (1997). https://doi.org/10.1007/s002329900186
Issue Date:
DOI: https://doi.org/10.1007/s002329900186