Comparison of the Reducing Power of Cancer Tumors and Tumors Produced by Filterable Viruses.

Abstract

There are in the literature contradictory reports with regard to the reducing power of tumor tissues. While Drew 1 and Heinlein 2 speak of a diminution of the reducing power of malignant tumors when compared to normal tissues, Voegtlin, Johnson and Dyer 3 maintain that such diminished power does not exist. Yaoi and Nakahara, 4 working with Rous chicken sarcoma, report that while this tumor when heated to 56° for half an hour and then incubated at 37°C. under a layer of vaseline, is unable to reduce methylene blue in the presence of sodium succinate, skeletal muscle submitted to the same treatment reduces the dye in 16 hours.

We have studied the reducing power of tumor tissues using the following technique. The tissue was cut in a manner similar to the Warburg technique for tissue respiration. This was placed in M/15 Sorensen's phosphates pH 7.38. Methylene blue was mostly used as indicators of reduction intensity. A stream of purified nitrogen was passed through the tubes. This kept the tissues in continuous movement throughout the entire column of liquid and facilitated the reduction of the dye. Rubber connections were entirely eliminated from the system. The tubes were kept in an air bath at 37.5°C.±0.3.

Seven different strains of rat's malignant tumors and one rabbit tumor have been studied. Our results show that tumor tissues have practically the same reducing power as normal tissues. When an easily oxidizable substrate (in our experiments sodium succinate) is added to the medium, the time of reduction is shortened, thus showing in all of these tumors the presence of the enzyme (succinodehydrogenase) which activates biological oxidation-reduction systems.