ABSTRACT
? carotene could decrease significantly the ear index and the quantity of Evan' s blue exudation that were skin photosensitive side actions in mice treated by photodynimic therapy ( PDT ) . The PGE 1 content in skin and the histamine content in skin and blood of mice were remarkably raised by raised by PDT. For example, the PGE 1 content in hematoporphyrin derivative group was 6.4 fold greater than that of control group. The PGE1 and histamine cotents were obviously decreased to nearly normal level by pretreatment with ? carotene. The results indicated that ? carotene can antagonise the skin photosensitive side action induced by PDT and the action was related to the decrease of PGE1 and histamine content in skin of mice. The cyclo-oxidase inhibitor indomethacin and the H1 receptor blocker benadryl could also decrease ear index and the quantity of Evan' s blue exudation