Microwave bioeffects in the erythrocyte are temperature and pO2 dependent: Cation permeability and protein shedding occur at the membrane phase transition

Abstract

Microwave exposure (2450 MHz, 60 mW/g, CW [continuous wave]) of rabbit erythrocytes increases Na passive transport only at membrane phase transition temperatures (Tc) of 17.degree.-19.degree. C. This permeability effect is enhanced for relative hypoxia which is characteristic of intracellular O2 tension (pO2 .ltoreq. 5 mm Hg). Neither the permeability nor the pO2 effects are observed in temperature-matched (.+-. 0.05.degree. C), sham-exposed controls. In addition, at Tc, microwave exposure is observed to induce the shedding or release of 2 erythrocyte proteins not seen in sham-exposed controls. The enhanced shedding of at least 7 other proteins all of MW .ltoreq. 28,000 D [daltons] was detected in the microwave-treated samples. Using sensitive silver staining it was estimated that .apprx. 450 fg of protein were shed per erythrocyte. Temperature and pO2 apparently are important influences on both functional and structural responses of cell membranes to microwave radiation.