Pflügers Archiv

, Volume 405, Supplement 1, pp S83–S88 | Cite as

Apical and basolateral membrane ionic channels in rabbit urinary bladder epithelium

  • Simon A. Lewis
  • John W. Hanrahan
Characterization of Ion Channels


This paper reviews the properties and regulation of single amiloride-sensitive Na+ channels in the apical membrane, and Cl and K+ channels in the basolateral membrane of rabbit urinary bladder. According to fluctuation analysis, there is an average of one amiloride-sensitive Na+ channel for every 40 μm2 of apical membrane. Each Na+ channel passes 0.7 pA of current under normal, short-circuit conditions. Apical channels are hydrolysed by the endogenous enzyme urokinase, which is released into the urine by the kidney. After exposure to urokinase, the Na+ channel loses its amiloride sensitivity, and eventually becomes unstable in the membrane. The selectivity and kinetic properties of single anion and K+ channels in the basolateral membrane were also studied using the patch clamp technique. The properties of these channels are discussed in terms of the regulation of transepithelial Na+ transport.

Key words

Urinary bladder Single Na+, K+ anion channels Channel turnover Channel density 


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Copyright information

© Springer-Verlag 1985

Authors and Affiliations

  • Simon A. Lewis
    • 1
  • John W. Hanrahan
    • 1
  1. 1.Department of PhysiologyYale Medical SchoolNew HavenUSA

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