Effect of hyperthermia on rabbit macrophages.

The effect of water-bath hyperthermia on rabbit peritoneal macrophages was studied in vitro. The cells were exposed to hyperthermia for 30 min to 4 hours and membrane transport of ions as measured by total and ouabain-inhibited 86Rb influx as well as membrane permeability for 86Rb and 51Cr-labelled intracellular proteins were investigated. Heat-treated macrophages were tested for their ability to phagocyte staphylococci and for reduction of nitroblue-tetrazolium. Moreover the effect of microwave whole-body hyperthermia on rabbit phogocytic cells was studied in vivo. Ion transport to macrophages was stimulated by both intensive (43 degrees C) and moderate (40 degrees C) hyperthermia. On the other hand exposition of the cells to 43 degrees C led to pronounced release of 86Rb and 51Cr from prelabelled cells. NBT reduction was generally decreased in macrophages exposed to 43 degrees C and increased in macrophages kept at 40 degrees C. Clearance of 32P-labelled staphylococci from peripheral blood of microwave-irradiated rabbits diminished when animals were exposed to microwave hyperthermia for f or 7 days (2 hours daily).