Determination of Heat Production from Erythrocytes in Normal Man and in Anemic Patients with Flow Microcalorimetry

Abstract

The heat production (H.P.) from washed human erythrocytes in heparin plasma was determined with flow microcalorimetry. The technique was found to be convenient and gave reproducible results. Coefficient of variation for duplicate determinations on one sample was 5.5 % and for determinations on samples from one individual on different days 10.9 %. The mean H.P. found in a population of 59 male and female healthy persons was 116 mW/l of erythrocytes, S.D.=17.6 mW/l, suggesting a reference range of 81–152 mW/1. Significant influence on the H.P. was demonstrated by changes in pH. A decrease of the H.P. was found in the presence of citrate, whereas only minor changes were found after centrifugation or ultracentrifugation of the samples. Neither did preservation at +4°C or room temperature for periods of 2–3 hours or at 37 °C for 1 hour markedly affect the H.P. of the erythrocytes. Increased H.P. was found in a number of samples from anemic patients, in whom the elevated H.P. appears to be related to the presence of young erythrocytes. Only one-third of the heat produced can be accounted for by calculating the enthalpy change due to glycolysis via the Embden-Meyerhof pathway. It is concluded that other metabolic pathways must contribute to the heat production.

Key Words:

• Anemia
• calorimetry
• erythrocyte metabolism