Abstract
Investigations of native blood of healthy people and of patients with acute leukemia have shown that the disease might be caused by a strongly reducing substance, which is presumably a virus. Evidence for this conclusion was obtained mainly by electron spin resonance (ESR) studies and by the determination of the catalase activity. ESR spectra of leukemic blood revealed an additional signal not present in spectra of healthy blood. Investigation of different blood fractions has shown that this signal is caused by a species present in the leukocytes only. Addition of reduced glutathione to healthy blood immediately after blood drawing resulted in the same signal. On the contrary, oxidizing substances, such as oxidized glutathione and KMnO4, added to the blood of leukemic patients immediately after its drawing, caused a disappearance of this signal depending on the concentration. Since the strongly reducing substance causes a reduction in the concentration of the oxidizing substances in biological systems, the H2O2 level should be also affected and, thus, the catalase activity, too. As expected, the activity of this enzyme in the leukemic blood seems to be considerably lower than in healthy blood.