Sarcoma‐180 cells are more sensitive to heat than are mouse normal tissues: Esophagus, stomach, small intestine, large intestine, liver, spleen, and kidney

Sensitivity of various mouse tissues to heat was determined using mouse sarcoma‐180 (S‐180) cells and normal tissues: esophagus, stomach, small intestine, large intestine, liver, spleen, and kidney. The in vitro succinate dehydrogenase inhibition (SDI) test was used. The succinate dehydrogenase (SD) activity of tissue fragments was assayed, following exposure to a temperature of 43°C (heat treatment) or 37°C (control) for 1, 2, 5, or 10 hr. The sensitivity to heat treatment was estimated by the percentage of SD activity of the heat‐treated cells, compared to that of the control cells. The decrease in SD activity following exposure to heat varied with the tissue. The SD activity decreased to a greater extent in the S‐180 cells than in the normal tissues. In the normal tissues, the order of sensitivity to heat was stomach, spleen, large intestine, small intestine, esophagus, kidney and liver. These results show that hyperthermia is tissue selective, hence heat treatment of a malignant lesion should be carefully designed.