Measurement temperature plays a pivotal role in the distribution of erythrocyte deformability after LPS

Abstract

Reductions in red blood cell membrane deformability (RBC_D) may perturb microcirculatory blood flow and impair tissue O₂‐availability. We investigated the effect of assay temperature on the distribution of RBC_D in endotoxin (LPS) incubated and control RBCs. Fresh blood from healthy rats was incubated with and without the presence of LPS for 6 hrs. An index of red blood cell membrane deformability, δ, was measured via the micropipette aspiration technique at 25°C and 37°C at 0, 2 and 6 hrs of incubation. The ATP content of RBC was measured by the luciferin–luciferase technique. At 25°C, LPS caused a significant decrease in mean δ after 2 and 6 hours incubation compared to controls (−10.0%, p=0.03 and −24.0%, p=0.03, respectively) characterized by a left shift in the distribution (skewness: −1.4). However, at 37°C a significant decrease in δ was only detected after 6 hrs of LPS incubation (−13.8%, p=0.01, compared to −5.1%, p=0.7 at 2 hours) and lacked the left shifted distribution (skewness: 0.2). No significant difference in ATP content of RBCs was observed between groups. We have shown that LPS incubation results in a significant decrease in RBC_D and that room temperature measurement of physical membrane properties may exaggerate the differences between normal and perturbed RBCs.