The Journal of Membrane Biology

, Volume 156 , Issue 1 , pp 45 –52

Regulation of Cl Secretion by Extracellular ATP in Cultured Mouse Endometrial Epithelium

Authors

  • H.C.  Chan
    • Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
  • C.Q.  Liu
    • Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
  • S.K.  Fong
    • Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
  • S.H.  Law
    • Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
  • L.J.  Wu
    • Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
  • E.  So
    • Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
  • Y.W.  Chung
    • Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
  • W.H.  Ko
    • Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
  • P.Y.D.  Wong
    • Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong

DOI: 10.1007/s002329900186

Cite this article as:
Chan, H., Liu, C., Fong, S. et al. J. Membrane Biol. (1997) 156: 45. doi:10.1007/s002329900186

Abstract.

The present study explored regulation of electrogenic ion transport across cultured mouse endometrial epithelium by extracellular ATP using the short-circuit current (ISC) and the patch-clamp techniques. The cultured endometrial monolayers responded to apical application of ATP with an increase in ISC 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 ISC, indicating that a substantial portion of the ATP-activated ISC was Cl-dependent. Amiloride at a concentration (10 μm) known to block Na+ channels was found to have no effect on the ATP-activated ISC excluding the involvement of Na+ absorption. Adenosine was found to have little effect on the ISC excluding the involvement of P1 receptors. The effect of UTP, a potent P2U receptor agonist on the ISC 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 ISC 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.

Key words: ATP — Endometrium — Epithelium — Ca2+— P2U-receptor — Cl− secretion

Copyright information

© 1997 Springer-Verlag New York Inc.