title: NMR studies of erythrocytes immobilized in agarose and alginate gels.
abstract: 31P and 13C NMR were used to study the energy metabolism in perfused, human erythrocytes. The erythrocytes were immobilized in agarose threads, Ca- or Ba-alginate beads, and Ba-alginate-coated agarose threads. Erythrocytes were easily washed out from the agarose threads, but not from alginate-containing gels. Various small molecules, such as hypophosphite, dimethyl methylphosphonate, and methylphosphonate, were taken up from the perfusion medium in a normal manner. In addition, the 2,3-bisphosphoglycerate (2,3-DPG) chemical shifts were sensitive to the oxygen partial pressure suggesting that O2 molecules were diffusing through the gel and modifying the binding of 2,3-DPG to hemoglobin. A combination of inosine and pyruvate stimulated the synthesis of 2,3-DPG, but only if inorganic phosphate was present in the perfusion medium. Inosine only resulted in a dramatic rise in the intracellular sugarphosphate concentrations. Furthermore, [2-13C]glucose was converted to [2-13C]lactate by immobilized cells at a rate which was comparable to that in a control suspension. In summary, immobilization in Ba-alginate-coated agarose threads was an efficient way of trapping human erythrocytes for whole cell NMR investigations.
authors.affiliation: Department of Biochemistry, University of Sydney, New South Wales, Australia.
authors.forename: P
authors.initials: P
authors.lastname: Lundberg
authors.forename: S J
authors.initials: SJ
authors.lastname: Berners-Price
authors.forename: S
authors.initials: S
authors.lastname: Roy
authors.forename: P W
authors.initials: PW
authors.lastname: Kuchel
mesh_terms: D000464:Alginates; D004163:Diphosphoglyceric Acids / Q000378:metabolism*; D004734:Energy Metabolism / Q000187:drug effects / Q000502:physiology*; D004912:Erythrocytes / Q000378:metabolism*; D005782:Gels; D006801:Humans; D066298:In Vitro Techniques; D007288:Inosine / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D010100:Oxygen / Q000502:physiology; D010313:Partial Pressure; D011773:Pyruvates / Q000494:pharmacology; D012685:Sepharose
chemical_list: D000464:Alginates; D004163:Diphosphoglyceric Acids; D005782:Gels; D011773:Pyruvates; D007288:Inosine; D012685:Sepharose; D010100:Oxygen