Some Antagonistic Effects of “Hematoporphyrin” and Protoporphyrin in Mice. ∗

Summary

Of 18 compounds studied, only protoporphyrin significantly protected mice injected with lethal doses of “hematoporphyrin.” Results of separate experiments with 277 mice showed (a) 14% survival in 76 mice which received “Hp” and vehicle alone, (b) 47% survival in 90 mice injected with protoporphyrin in addition to the “Hp” and kept in the dark, and (c) 30% survival in 109 mice injected with both porphyrins and kept in a room illuminated with fluorescent lights. The marked fall in total body oxygen uptake associated with “Hp” administration was decreased considerably by administration of protoporphyrin.