Hyperthermia: Its Effect on Proliferative and Plateau Phase Cell Cultures

This paper describes the response of cultured mammalian cells to periods of elevated temperatures. It was found that 43° C was necessary to produce substantial cell killing in aerated cells. Those made hypoxic in dense cultures were very sensitive to hyperthermia, cell killing taking place even at 41° C. Survival curves were obtained for proliferating and plateau phase cells exposed at 43° C for periods of 1 to 4 hours. There is no dramatic difference in sensitivity between cells in these two metabolic states, although the survival curve may be slightly steeper for plateau phase cells. Hyperthermia may be a useful adjunct to radiotherapy since these areas of the tumor which are most resistant to conventional x rays are sensitive to heat.