Comparison of two fluorescent probes for the measurement of erythrocyte membrane fluidity in renal dialysis patients.

Two fluorescent probes were used for the measurement of membrane fluidity in patients on haemodialysis and continuous ambulatory peritoneal dialysis. 1,6-Diphenyl-1,3,5-hexatriene (DPH) anisotropy gives an indication of lipid order and pyrene measures lateral diffusion through the membrane. Pyrene dimer/monomer ratio was significantly lower than controls in both pre-dialysis and post-dialysis samples but DPH anisotropy was unchanged. Both methods showed an increase in membrane fluidity across a 4 hour haemodialysis session. There was an increase in membrane fluidity in CAPD patient samples which was more marked using DPH than pyrene. These results suggest that the two probes give different but complementary information about changes in membrane fluidity and may be more informative when used together rather than singly.