Format

Send to:

Choose Destination
See comment in PubMed Commons below
Biochim Biophys Acta. 1993 Apr 22;1147(2):262-6.

Membrane potential determination in large unilamellar vesicles with hexakis(2-methoxyisobutylisonitrile)technetium(I).

Author information

  • 1Department of Radiology, Harvard Medical School, Boston, MA.

Abstract

The accumulation of the lipophilic cation hexakis (2-methoxyisobutylisonitrile)technetium (99mTc-MIBI) within large unilamellar vesicles made from egg phosphatidylcholine was examined as a function of time and membrane potential (Em). Equilibrium distribution occurred within minutes at 30 degrees C. The transmembrane distribution of Tc-MIBI was measured at Em = 0 mV and at a series of negative membrane potentials. The distribution of Tc-MIBI was in close agreement with the Nernst equation for passive distribution of a permeant ion across a bilayer, permitting the membrane potential to be predicted from Tc-MIBI distribution. In this respect, Tc-MIBI behaves similarly to other radioprobes of membrane potential, but with unique properties including high specific activity (10(9) Ci/mol), rapid kinetics of distribution, low potential-independent binding, and short half-life (6.02 h). The results indicate a mechanism for tissue accumulation of Tc-MIBI in vivo that may in part account for its utility in clinical imaging of ischemic myocardium.

PMID:
8476920
[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Loading ...
    Write to the Help Desk