Mechanism of decreased NMR-measured free magnesium in stored erythrocytes
P-31 NMR spectra of ebythrocytes stored with standard preservation media (ACD or CPDA-1) show a progressive upfield shift of the ..beta..P resonance of ATP. This would seem to indicate lower Mg-saturation of ATP and hence lower intracellular free magnesium (Mg/sub i/), but total intracellular Mg measured by AAS does not change. The authors have now observed similar spectral changes in erythrocytes stored in citrate-free media, hence the shifts are not an effect of citrate. Acidifying fresh blood to mimic the pH changes that occur with storage did not induce comparable shifts, nor did treatment of fresh blood with gramicidin, which causes Na/K redistribution across the erythrocyte membrane similar to that occurring with storage. The shifts were largely reversed when stored cells were incubated at 37/sup 0/C for 1 hr with fresh citrated or heparinized plasma. Such incubation also increased ATP levels but did not increased 2,3-DPG, hence the shifts do not depend on disappearance of 2,3-DPG. P-31 NMR of acid extracts of stored cells show accumulation of some pyrophosphate, but probably not enough to account for the large apparent decreased in Mg/sub i/. The NMR estimation of decreased Mg/sub i/ in stored blood does not appear to be an artifact related to alterations in monovalent cations or in binding of ligands to hemoglobin. A possible mechanism is increased binding of Mg to the cell membrane.
- Research Organization:
- New York Medical College, Valhalla, NY
- OSTI ID:
- 5020307
- Report Number(s):
- CONF-8606151-; TRN: 86-034826
- Journal Information:
- Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:6; Conference: 76. annual meeting of the Federation of American Society for Experimental Biology, Washington, DC, USA, 8 Jun 1986
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
62 RADIOLOGY AND NUCLEAR MEDICINE
ERYTHROCYTES
NMR SPECTRA
MAGNESIUM
BIOCHEMICAL REACTION KINETICS
ATP
CELL MEMBRANES
CHEMICAL SHIFT
NUCLEAR MAGNETIC RESONANCE
PHOSPHORUS 31
PYROPHOSPHATES
ALKALINE EARTH METALS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CELL CONSTITUENTS
ELEMENTS
ISOTOPES
KINETICS
LIGHT NUCLEI
MAGNETIC RESONANCE
MATERIALS
MEMBRANES
METALS
NUCLEI
NUCLEOTIDES
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
REACTION KINETICS
RESONANCE
SPECTRA
STABLE ISOTOPES
550201* - Biochemistry- Tracer Techniques
550600 - Medicine