title: A simpler procedure to study sodium-22 uptake (ouabain insensitive) in human erythrocytes.
abstract: We report a modification of the technique of Mahoney et al. (Blood 1982; 59: 439) for the determination of sodium-22 (22Na+) uptake in human erythrocytes. This modification facilitates the separation of 22Na+ taken up by erythrocytes from the free 22Na+ in the buffer by the addition of dibutyl phthalate, which forms an immiscible layer between the two. To further improve the sensitivity of 22Na+ uptake, we incubated a range of known numbers of erythrocytes with 22Na+ as opposed to the single cell suspension of known hematocrit used in Mahoney's et al. procedure (1). Erythrocytes are incubated in KCI buffer containing 2627 Bq (0.071 microCi) 22Na+ in a total volume of 0.5 mL for 0.5 h at 37 degrees C. Incubation is terminated by placing the tubes in ice for 10 min and the amount of 22Na+ taken up by the erythrocytes determined. We observe a linear relationship between erythrocyte concentrations (0.5 to 2.5 X 10(9) cells/mL) and percent uptake of 22Na+ (0.37 +/- 0.06 (1 SD) to 1.85 +/- 0.27 (1 SD) of the total 22Na+, respectively). The procedure is simple and sensitive, and can be used in clinical laboratories for the routine evaluation of 22Na+ uptake in erythrocytes.
authors.affiliation: Department of Medicine, Howard University, Washington, D.C. 20059.
authors.forename: K K
authors.initials: KK
authors.lastname: Gambhir
authors.forename: R
authors.initials: R
authors.lastname: Parui
authors.forename: S G
authors.initials: SG
authors.lastname: Nerurkar
authors.forename: N
authors.initials: N
authors.lastname: Dave
authors.forename: J
authors.initials: J
authors.lastname: Mathews
authors.forename: P P
authors.initials: PP
authors.lastname: Mehrotra
authors.forename: C L
authors.initials: CL
authors.lastname: Curry
mesh_terms: D044383:Black People; D004910:Erythrocyte Membrane / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D010042:Ouabain / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology; D012964:Sodium / Q000097:blood*; D012979:Sodium Radioisotopes
chemical_list: D012979:Sodium Radioisotopes; D010042:Ouabain; D011189:Potassium Chloride; D012964:Sodium