DEHYDROGENASE INACTIVATION IN OXYGEN POISONING

Abstract

Expts. were described in which the effects of O2 at high barometric pressure (7.6 atms.) on succino-dehydrogenase extracts of pork hearts were detd. The importance of elimination of violent or prolonged mechanical agitation of the extract, such as that of bubbling during its equilibration with the overlying gas, was stressed since such agitation in itself might alter de-hydrogenase activity. Exposure of the extracts from different hearts to O2 at 100 pounds pressure (7.6 atms.) for 2 1/2 hrs. resulted in decreased activity of the enzyme of from 9-50%. The variability in degree of inactivation might be one underlying cause for the lack of uniformity in susceptibility of intact animals to O2 poisoning. The inactivation of the dehydrogenase system in these in vitro expts. was an irreversible process. The relationship between this apparent irreversible inactivation of dehydrogenase extract and the degree of functional recovery which occurred in isolated tissue preps. following exposure to high pressure of O2 was discussed.