title: Gravimetric determination of the water concentration in whole blood, plasma and erythrocytes and correlations with hematological and clinicochemical parameters.
abstract: We have assessed gravimetric methods for determination of intravascular water, established whole blood-, plasma- and erythrocyte water reference values in a healthy volunteer group (n = 97, 48 females) and correlated these variables with 30 simultaneous hematological, clinicochemical and body parameters. The water standard was 55.56 mol/kg = 100 mass %. For erythrocyte water determination three methods were evaluated: 2 indirect methods were easy to perform, the third, using a hematocrit centrifuge, was the most reliable. Imprecision (within-batch coefficient of variation (CV), %) was excellent: whole blood 0.2, plasma 0.1, erythrocytes 0.7-2.2 and recoveries (means, %) 99.7-100.1. Serum water was found to be slightly higher than plasma water. Volunteer group, mean reference values, mass %: whole blood water 79.7, plasma water 91.2, erythrocyte water, three methods 66.2, 64.6 and 64.2, respectively. Females had mean 1.6 mass % higher whole blood water and 0.9-1.0 mass % higher erythrocyte water than males with no difference in plasma water. In the volunteer group whole blood water correlated strongly with hematocrit (r = -0.96), hemoglobin (r = -0.94) and erythrocytes (r = -0.85) and centrifuge hematocrit (r = -0.91). Plasma water correlated strongly with plasma total protein (r = -0.74, all correlations P < 0.001). Hemoglobin and hematocrit can serve as surrogate parameters for whole blood water when water determination is not available; total protein reflects plasma water.
authors: Department of Internal Medicine, State University, Groningen, The Netherlands.
authors: T H
authors: TH
authors: Lijnema
authors: J R
authors: JR
authors: Huizenga
authors: J
authors: J
authors: Jager
authors: A J
authors: AJ
authors: Mackor
authors: C H
authors: CH
authors: Gips
mesh_terms: D000328:Adult; D001769:Blood; D001798:Blood Proteins / Q000032:analysis*; D001834:Body Water; D004912:Erythrocytes / Q000737:chemistry*; D005260:Female; D006400:Hematocrit; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012727:Sex Characteristics
chemical_list: D001798:Blood Proteins; D006454:Hemoglobins