The effect of pentoxifylline on filterability of normal red blood cells and their adhesiveness to cultured endothelial cells.

The effects of pentoxifylline on filterability of normal red blood cells (RBCs) and their adhesiveness to cultured endothelial cells were investigated. In a balanced randomized and double blind trial, six healthy volunteers received 400 mg pentoxifylline or matching placebo 2 h before blood samples were taken. Filterability of RBCs of the subject while on pentoxifylline was significantly increased at 25 degrees C and 18 degrees C. Lowering of the filteration temperature to 18 degrees C significantly decreased filterability of RBCs. In vitro studies showed that 12 micrograms/ml pentoxifylline significantly increased RBC filterability and also partially prevented the effect of decreasing temperature on RBC filterability. 12 micrograms/ml pentoxifylline significantly decreased the adherence of normal RBCs to cultured endothelial cells. Our results suggest that in addition to increasing filterability of RBCs, pentoxifylline also decreased the adherence of RBCs to endothelial cells and this may contribute to its therapeutic effect.