spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by OPARKA,, K. J.
Right arrow Articles by HARRIS, N.
Right arrow Search for Related Content
PubMed
Right arrow Articles by OPARKA,, K. J.
Right arrow Articles by HARRIS, N.

Journal of Cell Science, Vol 99, 557-563, Copyright © 1975 by Company of Biologists

Submitted on February 7, 1991
Accepted on March 27, 1991

The drug probenecid inhibits the vacuolar accumulation of fluorescent anions in onion epidermal cells

K. J. OPARKA, 1, E. A. MURANT 1, K. M. WEIGHT 1, D. A. M. PRIOR 1, and N. HARRIS 2

1 Department of Cellular and Environmental Physiology, Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK
2 Department of Biological Sciences, University of Durham, South Road, Durham DH1 3LE, UK

The drug probenecid has been shown to inhibit the vacuolar accumulation of a range of fluorescent anions with differing pKa values (Lucifer Yellow CH, Cascade Blue hydrazide, sulphorhodamine G, carboxyfluorescein, FITC) in onion epidermal cells. In the absence of the drug, uptake occurred into the vacuole and was sensitive to extracellular pH. In the presence of the drug, the dyes accumulated exclusively in the cytoplasm and nucleus. Probenecid also induced vesiculation of the tonoplast and caused the cytoplasm to become polar, both of these structural changes being reversible by removal of the drug. In the case of the permeant FITC molecule, probenecid inhibited net uptake into the epidermal cells, and addition of the drug to cells that had already accumulated dye in the central vacuole resulted in rapid dye leakage across the tonoplast. However, the other more impermeant probes failed to leak to the cytoplasm once they had accumulated in the vacuole, even after prolonged exposures to probenecid. The data are discussed in the light of recent evidence for probenecid-sensitive carriers capable of transporting fluorescent anions across the endosomal membrane of macrophages and in relation to the concept of a detoxification system for the sequestration of xenobiotic anions by plant cells

Key words: anion transport, fluorescent probes, probenecid, tonoplast

Submitted on February 7, 1991
Accepted on March 27, 1991






© The Company of Biologists Ltd 1975