Some general regularities of synergistic interaction of hyperthermia with various physical and chemical inactivating agents

Abstract

Various cellular systems have been analysed for synergistic interactions of the simultaneous action of hyperthermia with physical agents including ionizing radiation, ultraviolet light, and ultrasound, and with chemical agents including thio-TEPA and cis-DDP. Some general rules of synergistic interaction were revealed. First, for every constant rate or intensity of exposure to physical factors or concentration of chemical agents, synergy can be observed only within a certain temperature range that is different for various cellular systems. Secondly, within this range, there is a specific temperature that maximizes the synergistic effect. Any deviation of temperature from the optimal one results in a reduction in synergy. Thirdly, the rate of exposure to physical agents or the concentration of chemical agents strongly influences the synergy; i.e. as the dose rate or concentration is reduced, the temperature for maximum synergism decreases. Possible interpretations of the mechanisms responsible for these relationships of synergy are discussed.

Response of cyclic AMP by DMSO differentiated HL‐60 cells exposed to electric interferential current after prestimulation

“…Petin and coworkers analyzed various cellular systems for synergistic interactions of two agents and revealed from this analysis some general rules [Petin et al, 2002]. First, for every intensity of a physical stressor or concentration of a chemical agent, synergy can be observed only within a certain intensity or concentration range of the second stressor.…”

“…Even two physical stressors are able to produce synergistic effects in biological systems, for example, heat and magnetic fields induced heat shock proteins [Junkersdorf et al, 2000], heat and ultrasound enhanced cell inactivation [ter Haar et al, 1988], as well as heat and UV light [Petin et al, 2002]. Petin and coworkers analyzed various cellular systems for synergistic interactions of two agents and revealed from this analysis some general rules [Petin et al, 2002].…”

“…Thirdly, the intensity or concentration of the first stressor strongly influences the synergy. In other words, there is sometimes only one combination of the intensity or concentration of the two stressors, that maximizes the synergistic effect [Petin et al, 2002].…”

IL-8 Release of HL-60 Cells Treated with Electric Currents of Different Wave Forms

“…In general, not only two chemical mediators can interact synergistically but also a chemical and a physical agent: for example, phorbol ester and magnetic fields (Tuinstra et al, 1998), concanavalin A and magnetic fields (Walleczek and Liburdy, 1990), or cis-diamminedichloroplatinum and heat (Urano et al, 1990). Even two physical stressors are able to produce synergistic effects in biological systems, for example heat and magnetic fields can induce heat shock proteins (Junkersdorf et al, 2000), heat and ultrasound enhance cell inactivation (ter Haar et al, 1988), as well as heat and UV light (Petin et al, 2002).…”

No Effect of 50 Hz 2.45 mT Magnetic Field on the Potency of Cisplatin, Mitomycin C, and Methotrexate inS. cerevisiae

“…The cytotoxicity of cisPt in combination with hyperthermia (41-441C) have been investigated by other authors who found that the high temperature potentiates cisPt cytotoxicity on tumor cells by increasing the drug uptake and the formation of DNA adducts (Ohno et al, 1994;Kusumoto et al, 1995;Ohtsubo et al, 1997;Petin et al, 2002;Haveman et al, 2005).…”