The use of isoperibol calorimetry for the study of age-related changes in glucose uptake by erythrocytes

Isoperibol solution calorimetry was used to determine in vitro erythrocyte glucose uptake changes as a function of erythrocyte age. Glucose concentrations were determined by phosphorylation with Mg < Superscript > 2+</Superscript >/ATP < Superscript > 2-</Superscript > in the presence of hexokinase. The differential heat of the standard reaction was found to be -70.3 kJ mol < Superscript >-1 </Superscript > (-16.8 kcal mol < Superscript >-1 </Superscript >). Lower amounts of glucose were taken up by &apos; expired,&apos; older than 90 days, cells (0.37 mmol/5 mL packed cells) than by &apos; fresh,&apos; immediately after blood collection, cells (0.87 mmol/5 mL packed cells). Statistical analyses of the data revealed significant differences in extent of glucose uptake between fresh cells and expired cells (p < 0.05).