A new method of measuring red cell deformability and the effects of pentoxifylline.

The effect of pentoxifylline on red cell deformability was studied using a new device of a polycarbonate membrane filter ("Nuclepore') and a differential pressure type transducer. Differential pressure fluctuations due to the passage of red cells through the "Nuclepore' membrane were recorded as a differential pressure curve of red cell filtration. Red cell deformability was measured with a diluted red cell suspension (10 x 10(4)/mm3) in this buffered NaCl solution of normal osmotic pressure, 300m0sm/l as a suspending medium. Blood samples were taken from 9 healthy subjects and 26 patients with diabetes mellitus, liver disease and miscellaneous diseases. The ability of pentoxifylline to modify red cell deformability was investigated using concentrations of 20 micrograms/ml and 40 micrograms/ml in diluted red cell suspension which was incubated for 2 hours of 37 degrees C. Changes in red cell deformability were estimated from the gap between two differential pressure curves recorded in blood suspension with or without pentoxifylline. Addition of pentoxifylline increases red cell deformability in both groups of blood suspension in healthy subjects and patients. A significant increase in red cell deformability was observed in 40% of samples with the addition of 29 micrograms/ml pentoxifylline and in 77% of those with 40 micrograms/ml, respectively.