ABSTRACT
BACKGROUND: There are some studies proposing cell membrane may be one of target cell regions for electromagnetic biological effects. However, reports responsible for cellular membrane permeability and cellular biological effects after electromagnetic irradiation are few. OBJECTIVE: This study was designed to investigate the correlations of low-power millimeter wave irradiation to cellular membrane permeability and apoptosis of HL60.DESIGN: Controlled experiment.SETTING: Thus study was performed at the Medical Experimental Central Laboratory, Guangzhou General Hospital,Guangzhou Military Area Command of Chinese PLA between November 2006 and April 2007. MATERIALS: The human leukemic cell lines HL60 were kindly provided by Medical Experimental Center of Guangzhou Military Area Command of Chinese PLA and HD-413.2HPSG 100 millimeter wave irradiation generator was developed by Xi'an Hengda Microwave Technology Development Company, China. METHODS: HL60 cells were irradiated by millimeter wave at frequency of 41.32 GHz and mean power density of 2 mW/cm2, and divided into five groups according to the irradiation time (0, 15, 30, 45, 60 minutes groups).MAIN OUTCOME MEASURES: Lanthanum tracing was used to observe intracellular and extracellular lanthanum particles distribution and evaluate the change of cellular membrane permeability; ultrastructure and morphological characteristics of HL60 cells were observed through an transmission electron microscope; Quantitative analysis of apoptotic cells was performed by in situ marking method. RESULTS: In the 45 and 60 minutes groups, a small amount of lanthanum particles in the cytoplasm, swollen mitochondria, expanded rough endoplasmic reticulum, and obvious apoptosis were detected by ultrastructure observation. TUNEL staining showed, compared with the 0 minute control group, the apoptosis rate showed a trend of elevation in all the irradiation groups, particularly in the 45 and 60 minutes groups. CONCLUSION: Low-power millimeter wave irradiation on HL60 cells can lead to an increase in cellular membrane permeability of HL60, which may be one of the primary causes for promoting apoptosis and producing other biological effects.
ABSTRACT
During the electroporation cell membrane conductivity increases dramatically, so the analytical model for calculating the transmembrane voltage (TMV) induced on an unpermeabilized cell membrane in suspensions can not be used in this case. An analytical model for the TMV induced on a permeabilized cell membrane in suspensions exposed to a high voltage DC pulse field was built. First, a permeabilized cell was replaced by a sphere cell having the equivalent conductivity. Then the average field inside the permeabilized cell suspensions was calculated according to the effective medium theory. Finally, based on the analytical solution for the TMV on a single unpermeabilized cell, an analytical model for the TMV on a permeabilized cell in suspensions was derived. The model shows that the TMV depends on parameters such as the external electric field, critical angle of electroporation, cell radium, conductivity of the cytoplasm, membrane and external medium, cell arrangement and cell volume fraction.
Subject(s)
Humans , Cell Membrane Permeability , Electric Conductivity , Electromagnetic Fields , Electrophysiology , Electroporation , Membrane Potentials , Models, Biological , PulseABSTRACT
Low intensity millimeter(6mm,50GHz,100mW) wave was used to irradiate to 15 blood samples. The radiation time respectively were 15min、30min and 60min.Series rheological and biophysical parameters about the erythrocyte were systemically tested. There included viscosity of blood 、deformability and congregating ability of erythrocyte、hemolysical fragility 、anion transport in erythrocyte membranes and configuration of erythrocyte etc. From the point of biophysics, the biological effects of low intensity MMW to cells were investigated.