Indomethacin reduces the skin thermal damage in hyperthermic treatment of experimental malignant tumors.

Indomethacin (Ind), an inhibitor of prostaglandin synthesis, was previously shown to increase the thermosensitivity of murine tumors. The potency of drug to modify the thermal response of murine skin has been evaluated in mice heated in water bath at 44 degrees C for 30, 60 and 90 min. Ind was administered subcutaneously (s.c.) at dose of 5 mg/kg body weight (b.w.) 1.5 h before heating. The mouse foot skin reactions (FSR) were assessed using the scoring system of Urano et al (1979). The severity of skin thermal damage was decreased markedly by Ind. At the time when heating of the control group at 44 degrees C for 60 min resulted in the irreversible FSR in some mice, pretreatment with Ind before heating lead to the complete recovery from the heat damage in all mice. Similarly, after heating at 44 degrees C for 90 min, the degree of FSR was diminished by Ind from score 4.5 to score 2. It is concluded that Ind selectively protected normal skin during the hyperthermic treatment. Further clinical study is warranted.