Effect of Chronic Oral Pentoxifylline Administration on Murine Erythrocyte Deformability

Background: Pentoxifylline has been reported to increase radiation sensitivityin vivo.We sought to evaluate whether this effect is mediated by changes in murine erythrocyte flexibility. Methods: Pentoxifylline was administered via liquid or solid diet to young adult male CF-1 mice for 1–6 weeks. After 1, 3, and 6 weeks of drug administration, plasma levels of pentoxifylline and major derivatives were measured and erythrocyte deformability was assessed by rheoscopy, a technique which permits direct measurement of individual cellular dimensions. Results: Contrary to prior reports, we found no discernible effect of the drug on erythrocyte deformability. Conclusions: The beneficial effect of pentoxifylline administration on radiation sensitivity in tumor-bearing mice is mediated by other mechanisms.