Uptake of cesium ions by human erythrocytes and perfused rat heart: a cesium-133 NMR study.
Cesium-133 NMR studies have been carried out on suspended human erythrocytes and on perfused rat hearts in media containing CsCl. The resulting spectra exhibit two sharp resonances, arising from intra- and extracellular Cs+, separated in chemical shift by 1.0-1.4 ppm. Thus, intra- and extracellular resonances are easily resolved without the addition of paramagnetic shift reagents required to resolve resonances of the other alkali metal ions. Spin-lattice relaxation times in all cases are monoexponential and significantly shorter (3-4 times) for the intracellular component. When corrections are made for the pulse repetition rate, the total intensity of the intracellular and extracellular Cs+ resonances in erythrocytes is conserved, implying total observability of the intracellular pool. The uptake of Cs+ by erythrocytes occurs at approximately one-third the reported rate for K+ and was reduced by a factor of 2 upon addition of ouabain to the sample. These results indicate that 133Cs NMR is a promising tool for studying the distribution and transport of cesium ions in biological systems and, in some cases such as uptake by cellular Na,K-ATPase, for analysis of K+ ion metabolism.
Davis
D G
DG
Laboratory of Molecular Biophysics, National Institute of Environmental Health Sciences, Research Triangle Park, North Carolina 27709.
Murphy
E
E
London
R E
RE
D000818:Animals; D001692:Biological Transport; D002586:Cesium / Q000097:blood / Q000378:metabolism*; D002712:Chlorides; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009206:Myocardium / Q000378:metabolism*; D010477:Perfusion; D051381:Rats; D011919:Rats, Inbred Strains
D002712:Chlorides; D002586:Cesium; C028019:cesium chloride