Influence of the hemoglobin solution HBOC-201 on tissue oxygenation in the rat R1H-tumor

Abstract

Background: HBOC-201 is an ultra purified bovine hemoglobin solution. It has already been used in clinical phase II/III trials for emergency treatments. Animal experiments have shown that HBOC-201 is highly effective in tissue oxygenation. The study was performed in order to assess the potential of low dose HBOC-201 to improve tumor oxygenation. Methods: 30 rats with a subcutaneously growing rhabdomyosarcoma R1H tumor were randomly assigned either to be ventilated with carbogen (n = 10), or to receive an IV injection of 0.3 g/kg HBOC-201 (n = 10) or a combination of 0.3 g/kg HBOC-201 and carbogen breathing (n = 10). Under general anesthesia the effects of the respective treatment on the tissue oxygen tension (tpO2) of the tumor were determined using a flexible stationary probe at baseline (b) and 15 and 60 min after application of the respective medication. Results: HBOC-201 alone failed to improve tumor tpO2 (b: 1.3 ± 1.2 mmHg; 15 min: 1.4 ± 1 mmHg; 60 min: 1 ± 1 mmHg). In combination with carbogen the mean tpO2 of the tumor raised in comparison to baseline values (b: 3.1 ± 4.6 mmHg; mmHg; 15 min: 8.5 ± 11* mmHg; 60 min: 4.8 ± 5 mmHg; *p < 0.05 vs. b), but this effect was less pronounced than the increase in tpO2 by carbogen alone (b: 3.4 ± 3.4 mmHg; 15 min: 9 ± 10* mmHg; 60 min: 13 ± 19* mmHg; *p < 0.05 vs. b). Conclusion: The application of low dose hemoglobin solution HBOC-201 does not result in improvement of tissue oxygenation in the rat rhabdomyosarcoma R1H. Copyright © Taylor & Francis, Inc.