Cortisone-Like Effect of Hematophorphyrin and Sunlight on Anaphylaxis in Mice. ∗

Summary

Forty-nine of 184 control horse serum-sensitized mice (27%) survived a shocking dose of horse serum. Three to 15 minutes exposure of sensitized mice to sunlight has no influence on survivorship in these mice. Low doses (0.6 - 2 mg) of hematoporphyrin significantly increased the lethal effects of anaphylaxis in 54 horse serum-sensitized mice since only 8% survived. A small dose of hematoporphyrin (2 mg) and 3-15 minutes exposure to sunlight decreased lethality of shocking doses of horse serum administered to sensitized mice. The protection afforded was directly related to the length of exposure. Twenty-four of 26 sensitized mice (92%) injected with 2 mg of hematoporphyrin and subsequently exposed for 15 minutes to direct sunlight survived a shocking dose of antigen. This is an effect similar to that exerted by cortisone and of the same order of magnitude.