The enzymic hydrolysis of adenosine triphosphate by liver mitochondria. I. Activities at different pH values.

more toxic by intraperitoneal injection than any of the simple peroxides with which it was compared. Autoxidized methyl linoleate was less toxic than most of the simple peroxides. 5. The LD50 of autoxidized linoleic acid (0.26 ,mole of peroxide/g.) was only slightly higher than the mean increase of peroxide previously found in mice after 950r. of X-rays (0.22 lamole/g.). 6. Injected peroxides kill more quickly than radiation, but thismay be a question ofdistribution. 7. The evidence is consistent with the view that radiation toxicity is due to initiation of chain autoxidation of essential fatty acids producing lethal doses of peroxides in sites not reached by vitamin E..