Comparative Nuclear Magnetic Resonance Studies of Diffusional Water Permeability of Red Blood Cells from Different Species. XI. Horses Introduced to Australia and European Horses (Equus caballus)

2000 ◽  
Vol 10 (3) ◽  
pp. 138-143 ◽  
Author(s):  
Gh. Benga ◽  
H. Matei ◽  
L. Frenţescu ◽  
B. E. Chapman ◽  
P. W. Kuchel
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Red Blood Cells ◽  
Water Permeability ◽  
Blood Cells ◽  
Equus Caballus ◽  
Magnetic Resonance Studies ◽  
Nuclear Magnetic

Nuclear magnetic resonance measurement of cytosolic free calcium levels in human red blood cells

1986 ◽  
Vol 251 (4) ◽  
pp. C496-C504 ◽  
Author(s):  
E. Murphy ◽  
L. Levy ◽  
L. R. Berkowitz ◽  
E. P. Orringer ◽  
S. A. Gabel ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Atp Depletion ◽  
Free Calcium ◽  
Ionophore A23187 ◽  
Tetraacetic Acid ◽  
Acetoxymethyl Ester ◽  
Nuclear Magnetic

Red blood cells were loaded with 1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N',N'-tetraacetic acid (FBAPTA) by incubation with 50 microM of the acetoxymethyl ester (FBAPTA-AM), and cytosolic free Ca2+ was monitored with 19F-nuclear magnetic resonance (NMR). Loading with 50 microM FBAPTA-AM, which results in a final FBAPTA level of approximately 0.5 mM, caused only a 25-30% fall in cell ATP as measured by 31P-NMR when 5 mM pyruvate was present. Leakage of the NMR active Ca2+ indicator, which results from cell lysis, was corrected for with the addition of extracellular Eu3+ ions, extracellular ethyleneglycol-bis(beta-aminoethylether)-N,N'-tetraacetic acid (EGTA), or washing. With this method, we have found basal levels of cytosolic free Ca2+ averaging 61 +/- 6 nM (means +/- SE, n = 19). When the intracellular level of FBAPTA was varied from 0.1 to 1.0 mM, there was no correlation between the level of cytosolic free Ca2+ and the level of loading with FBAPTA. Addition of 10 microM of the Ca2+ ionophore A23187 with extracellular Ca2+ set at different levels by Ca2+-EGTA buffers caused an increase in cytosolic free Ca2+ as expected. Furthermore, ATP depletion caused a two- to three-fold increase in cytosolic free Ca2+, consistent with inhibition of Ca2+ efflux via that Ca2+-ATPase.

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