Absorptive apical amiloride-sensitive Na+ conductance in human endometrial epithelium

• Published in: The Journal of physiology Vol. 513; no. 2; pp. 443 - 452
• Main Authors: Matthews, C. Jane, McEwan, Gordon T. A., Redfern, Christopher P. F., Thomas, Eric J., Hirst, Barry H.
• Format: Journal Article
• Language: English
• Published: Oxford, UK The Physiological Society 01.12.1998; Blackwell Science Ltd; Blackwell Science Inc
• Subjects: Absorption; Amiloride - pharmacology; Barium - pharmacology; Cell Membrane - physiology; Cells, Cultured; Electric Conductivity; Electrophysiology; Endometrium - cytology; Endometrium - drug effects; Endometrium - physiology; Epithelial Cells - drug effects; Epithelial Cells - physiology; Female; Humans; Nitrobenzoates - pharmacology; Original; Ouabain - pharmacology; Sodium - physiology
• ISSN: 0022-3751; 1469-7793
• DOI: 10.1111/j.1469-7793.1998.443bb.x

Human endometrial epithelial cells cultured on porous tissue culture supports formed tight, polarized epithelial monolayers with features characteristic of tight epithelia. Endometrial epithelial layers generated significant transepithelial electrical resistance (750 Ω cm 2 ) and potential difference (15.3 mV), with an inward short-circuit current ( I sc ; 20.5 μA cm −2 ). The I sc was linearly proportional to the external Na + concentration and was abolished in the absence of Na + . The I sc was sensitive to apical amiloride. Net 22 Na + flux was in the absorptive apical to basolateral direction and fully accounted for the inward I sc . In addition, apical to basolateral and net 22 Na + transport were reduced in the presence of amiloride. The I sc was also sensitive to addition of ouabain and Ba 2+ to the basal solution, consistent with a role for basolateral Na + −K + -ATPase and K + channels in generation of the current. These data demonstrate that human endometrial epithelial cells in primary culture produce tight, functional monolayers on permeable supports. We provide the first evidence that human endometrial epithelial cells have an inward I sc accounted for by an amiloride-sensitive Na + conductance. The Na + -absorptive function of the endometrium may provide an appropriate environment for sperm function and embryo growth.