alexa Mechanisms of fluid secretion by polycystic epithelia.


Biochemistry & Physiology: Open Access

Author(s): Sullivan LP, Grantham JJ

Abstract Share this page

Abstract We have sought to determine the mechanisms driving fluid secretion by the cystic epithelium in autosomal dominant polycystic kidney disease (ADPKD). We have performed in vitro experiments on intact cysts dissected from discarded ADPKD kidneys, on monolayers of cells cultured from the cystic epithelium and on microcysts clonally derived from single cultured cells. These preparations absorb fluid in the control state but secrete fluid in response to native cyst fluid, to adenylate cyclase agonists and to permeant analogues of cAMP. Measurements of short-circuit current and transepithelial voltage in the monolayers indicate that anion secretion must drive the fluid secretion. Fluid secretion by the intact cysts was inhibited by basolateral application of ouabain but not by apical application. The effect of ouabain on fluid secretion and short-circuit current in the monolayers followed the same pattern. Thus the functional Na,K-ATPase enzyme complex is located only in the basolateral membrane of the cystic cells and serves to maintain the transmembrane chemical and electrical gradients that drive anion secretion by other transport mechanisms. Fluid secretion and short-circuit current in the cultured monolayers was inhibited by the basolateral application of the Na-K-2Cl cotransporter inhibitors, bumetanide and furosemide, and by apical application of the chloride channel blocker, diphenylamine-2-carboxylate (DPC). These data suggest that chloride is the anion that is actively secreted. Preliminary experiments utilizing the monolayers and the microcysts and measuring cell chloride concentration and chloride efflux across the apical membrane support this conclusion. Other preliminary data indicate that the cystic fibrosis transmembrane conductance regulator is present in the apical membrane. Thus active chloride transport generates fluid secretion by the cystic epithelium.
This article was published in Kidney Int and referenced in Biochemistry & Physiology: Open Access

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

  • 9th International Conference on Structural Biology
    September 18-20, 2017 Zurich, Switzerland

  •  2nd International Conference on Biochemistry
    Sep 21-22, 2017, Macau, Hong Kong
  • 2nd International Conference on Biochemistry
    September 28-29, 2017 Dubai, UAE

  • 3rd Annual Congress on Bioscience
    October 16-17, 2017 Dubai,UAE

  • 3rd International Conference on Transcriptomics
    October 30 - November 01, 2017 Bangkok, Thailand

  • 3rd International Conference on Genetic and Protein Engineering (10 Plenary Forums - 1 Event)
    November 08-09, 2017 Las Vegas, USA

Relevant Topics

Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version