QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Wang, Y. Articles by Telfer, W. H. Search for Related Content PubMed PubMed Citation Articles by Wang, Y. Articles by Telfer, W. H. Social Bookmarking                         What's this?

Journal of Experimental Biology, Vol 201, Issue 10 1627-1635, Copyright © 1998 by Company of Biologists

JOURNAL ARTICLES

Cyclic-AMP-induced water uptake in a moth ovary: inhibition by bafilomycin and anthracene-9-carboxylic acid

Y Wang and WH Telfer
Department of Biology, University of Pennsylvania, Philadelphia, PA 19104-6018, USA.

The ion physiology of osmotic swelling and a consequent loss of epithelial patency was examined in the ovaries of the moth Hyalophora cecropia. After 30 min in the presence of an activator of cyclic-AMP-dependent protein kinase (PKA), the membrane potentials of both oocyte and follicle cells had hyperpolarized by approximately 30 %, cytoplasmic pH had dropped from 7.26 to 7.06, a normally low Cl- conductance had increased and the follicle cells had begun to swell. Since ion distribution studies have indicated that conductance increases should depolarize membranes in this system, it is proposed that hyperpolarization may be effected by an azide-inhibitable component of the membrane potential. Nanomolar levels of bafilomycin, an inhibitor of H+ V-ATPase, blocked the active component and prevented osmotic swelling in response to PKA activation. Under a variety of circumstances, correlations were seen between membrane potential and cytoplasmic pH, suggesting that substrate availability to the proton pump may contribute to hyperpolarization. H+ V-ATPases are known to energize ion and water transport across many epithelia, but in this case they generate water absorption by the epithelium. The increase in Cl- conductance was also required for the swelling response: the Cl- channel blocker anthracene-9-carboxylic acid prevented both swelling and hyperpolarization, as did Cl- substitution in the medium. Differences in isotope loading rates between 36Cl- and 86Rb+ suggested that, after PKA activation, Cl- functions other than as a counterion for K+ uptake.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				B. Etschmann, K. S. Heipertz, A. von der Schulenburg, and M. Schweigel A vH+-ATPase is present in cultured sheep ruminal epithelial cells Am J Physiol Gastrointest Liver Physiol, December 1, 2006; 291(6): G1171 - G1179. [Abstract] [Full Text] [PDF]