These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Inhibition and stimulation of K+ transport across the frog erythrocyte membrane by furosemide, DIOA, DIDS and quinine.
    Author: Gusev GP, Lapin AV, Agalakova NI.
    Journal: Gen Physiol Biophys; 1999 Sep; 18(3):269-82. PubMed ID: 10703743.
    Abstract:
    Frog erythrocytes were incubated in iso- or hypotonic media containing 10 mmol/l Rb+ and 0.1 mmol/l ouabain and both Rb+ uptake and K+ loss were measured simultaneously. Rb+ uptake by frog red cells in iso- and hypotonic media was reduced by 30-60% in the presence of 0.01-0.1 mmol/l [(dihydroindenyl)oxy] alkanoic acid (DIOA) or 0.5-1.0 mmol/l furosemide. Furosemide inhibited K+ loss from frog erythrocytes incubated in hypotonic media but did not affect it in isotonic media. DIOA at a concentration of 0.05 mmol/l inhibited of K+ loss from frog erythrocytes in both iso- and hypotonic media. At the concentrations of 0.01 and 0.02 mmol/l DIOA significantly suppressed K+ loss in a K+-free chloride medium but not in a K+-free nitrate medium. The Cl(-)-dependent K+ loss was completely blocked at a concentration of 0.1 mmol/l DIOA and the concentration required for 50% inhibition of K-Cl cotransport was approximately 0.015 mmol/l. However, the inhibitory effect of DIOA on K-Cl cotransport was masked by an opposite stimulatory effect on K+ transport which was also observed in nitrate medium. Quinine in a concentration of 0.2-1.0 mmol/l was able to inhibit Rb+ uptake and K+ loss only in hypotonic media. In isotonic media, quinine produced a stimulation of Rb+ uptake and K+ loss. A three to five-fold activation of Rb+ uptake and K+ loss was consistently observed in frog erythrocytes treated with 0.05-0.2 mmol/l 4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid (DIDS). In contrast, another stilbene derivative 4-acetamido-4'-isothiocyanatostilbene-2,2'-disulphonic acid (SITS) had no effect on K+ transport in the cells. Thus, of these drugs tested in the present study only DIOA at low concentrations may be considered as a selective blocker of the K-Cl cotransporter in the frog red blood cells.
    [Abstract] [Full Text] [Related] [New Search]