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: Ionic movements mediated by monensin in frog skeletal muscle.
    Author: Hoya A, Venosa RA.
    Journal: Biochim Biophys Acta; 1992 Feb 17; 1104(1):123-31. PubMed ID: 1550839.
    Abstract:
    Monensin-mediated ionic movements were studied in frog skeletal muscle. The ionophore, which forms electrically neutral complexes with monovalent cations, induced dose dependent fluxes of Na+, K+ and H+ in and out of the fibers. Monensin concentrations ([MON]) ranged from 2 to 40 microM. In the presence of normal Ringer's solution the following maximum ionic exchanges were generated by monensin (in pmol cm-2 s-1): (1) Nai+/Nao+ 112, (2) Nai+/Ho+ 30.7, (3) Ki+/Nao+ 14.2 (4) Hi+/Nao+ 49. The maximum net fluxes produced by these exchanges (i.e. for [MON] = infinity) are (in pmol cm-2 s-1): Na+ (inward) 32.5, K+ (outward) 14.2, H+ (outward) 18.3. The last one appears to be largely offset by a passive (monensin-independent) H+ influx down an inwardly directed electrochemical gradient promoted by pH reduction of the T-tubular lumen content as a consequence of the monensin-mediated net H+ efflux. Maximum unidirectional cationic fluxes mediated by monensin amounted to 206 pmol cm-2 s-1 and had the following composition: influx: 85% Na+ and 15% H+; efflux: 69% Na+, 7% K+, 24% H+.
    [Abstract] [Full Text] [Related] [New Search]