Microcirculatory and pH Alterations in Isotransplanted Rat and Xenotransplanted Human Tumors Associated with Hyperthermia

The rationale for considering the use of hyperthermia as an antitumor agent is based on three different mechanisms of action depending on the hyperthermia levels chosen: At moderate hyperthermia levels (40°–42.5° C) heat can increase the radiosensitivity and/or the chemosensitivity. At higher tissue temperatures ( > 42.5° C) hyperthermia acts as a cytotoxic agent since mammalian cells die after heating in a temperature-, time-, and cell cycle-dependent manner. Besides direct effects on the cell membranes, on the cytoskeleton, on metabolic processes, on DNA replication, and on RNA and protein synthesis, indirect effects distinctly modulating the anticancer action of heat have to be considere…