Evidence for electrogenic Na-glucose cotransport in tracheal epithelium

✍ Scribed by Liesbet Joris; Paul M. Quinton

• Book ID: 104746479
• Publisher: Springer
• Year: 1989
• Tongue: English
• Weight: 260 KB
• Volume: 415
• Category: Article
• ISSN: 0031-6768
• DOI: 10.1007/bf00373149

✦ Synopsis

We demonstrate that electrogenic glucose coupled Na + absorption accounts for about 20% of the residual, amiloride and CI-insensitive, Na + transport in isolated (equine) trachea. Either glucose removal from the mucosal side or addition of l0 -4 M phloridzin, a known pharmacological inhibitor of Na-glucose cotransport in small intestine and kidney proximal tubule, results in depolarization (lumen referenced to bath) of the transepithelial potential difference (V t) and in a significant decrease of the equivalent short circuit current Ieq by 4 mV and 4 ~A/cm 2, respectively, without affecting the transepithelial resistance (Rt). Neither glucose removal nor the application of phloridzin on the basolateral side have a significant or consistent effect on the bioelectric parameters.