Microcalorimetric measurements of heat production in erythrocytes of patients with chronic uraemia.

The metabolic activity in the erythrocytes of 12 patients with chronic uraemia was studied by a microcalorimetric method. When the pentose phosphate pathway activity of erythrocytes was stimulated with 10(-4) M methylene blue (MB), significantly higher levels of heat effect were found in the group of uraemic patients than in a group of healthy subjects. The difference between the 2 groups was higher in plasma (p less than 0.005) than in phosphate buffer suspensions (p less than 0.05). The ratio between the mean values for the 2 groups was 1.18 both in plasma and in phosphate-buffer. Also for unstimulated cells the heat effect values were higher in the group of uraemic patients than in the control group. The ratio was 1.21 (p less than 0.005) and 1.14 (p less than 0.05) for plasma and buffer suspensions, respectively. The present results are in disagreement with previous reports, according to which haemolytic anaemia among uraemic patients is due to decreased erythrocyte aerobic metabolism.