Affiliations: The A.C. Burton Vascular Biology Laboratory, London Health Sciences Centre, and the Department of Medical Biophysics, University of Western Ontario, London, Ontario, Canada N6A 5C1 | Department of Medicine, Sunnybrook and Woman's College Hospital, Toronto, Ontario, Canada M4N 3M5
Note: [] Address for correspondence: Dr. Christopher G. Ellis, Department of Medical Biophysics, Medical Sciences Building, University of Western Ontario, London, Ontario, Canada N6A 5C1. Tel.: +1 519 661 3100; Fax: +1 519 661 2123; E‐mail: [email protected].
Abstract: Reductions in red blood cell membrane deformability (RBCD) may perturb microcirculatory blood flow and impair tissue O2‐availability. We investigated the effect of assay temperature on the distribution of RBCD 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 RBCD and that room temperature measurement of physical membrane properties may exaggerate the differences between normal and perturbed RBCs.
Journal: Biorheology, vol. 38, no. 5-6, pp. 439-448, 2001
