Early change of adenosine triphosphate levels in L5178Y cells during hyperthermia

The time course of the change of cellular ATP level was studied in L5178Y cells exposed continuously to various temperatures and compared with that of cell death determined by means of a dye-exclusion test. The ATP level first increased at all temperatures tested and then decreased at temperatures higher than 42 degrees. The onset of this decrease always preceded the beginning of cell death. The results support the idea that the cellular lethality of heat treatment is well correlated with cellular ATP content in L5178Y cells.