Secretagogues increase apical membrane conductance of isolated bullfrog corneal epithelium pretreated with loop diuretics.

Pflügers Archiv : European journal of physiology
H F Schoen

Abstract

Bullfrog (Rana catesbeiana) corneas were mounted in an Ussing type chamber and impaled with an intracellular microelectrode and the short circuit current was inhibited by pretreatment with the loop diuretics furosemide (0.3 to 1 mM) or bumetanide (10 to 100 microM). Subsequent addition of the secretagogues prostaglandin E2, forskolin, or 3-isobutyl-1-methylxanthine (IBMX) caused the fractional voltage drop of the apical barrier to decrease from 0.72 +/- 0.05 to 0.48 +/- 0.04 and the chloride-dependent conductance to increase by 0.15 +/- 0.03 mS/cm2, but caused only a small, transient increase in short circuit current. The loop diuretics by themselves always greatly reduced the short circuit current but did not consistently reduce conductance or fractional voltage drop of the apical membrane. Because the secretagogues were able to increase the apical membrane conductance of diuretic-inhibited corneas without large effects on the short circuit current, the loop diuretics must have a major effect at a site other than the apical membrane Cl- conductance, presumably at the basolateral membrane. An additional effect of the loop diuretics at the apical membrane is also possible.

References

May 1, 1977·The Journal of General Physiology·S I Helman, R S Fisher
Dec 1, 1987·The Journal of General Physiology·D W LandryQ Al-Awqati
Jan 1, 1987·The Journal of Membrane Biology·P S ReinachG Klemperer
Sep 1, 1986·The American Journal of Physiology·O A CandiaT C Chu
Oct 1, 1987·The American Journal of Physiology·J M Wolosin, O A Candia
Aug 1, 1985·The Journal of General Physiology·H F Schoen, D Erlij
Jan 1, 1985·The Journal of Membrane Biology·P Reinach, W Nagel
Dec 1, 1984·Pflügers Archiv : European journal of physiology·R Greger, E Schlatter
Nov 1, 1983·The American Journal of Physiology·J H WiddicombeE Highland
Sep 1, 1983·Pflügers Archiv : European journal of physiology·R GregerC Weidtke
Jan 1, 1983·The Journal of Membrane Biology·M J WelshR A Frizzell
Jan 1, 1983·The Journal of Membrane Biology·M J Welsh
Nov 25, 1982·Nature·M W MuschR A Frizzell

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Citations

Apr 27, 2004·Experimental Eye Research·Oscar A Candia

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