Gaber Mohamed H, Abd El Halim N, Khalil W A
Biophysics Department, Faculty of Science, Cairo University, Giza, Egypt.
Bioelectromagnetics. 2005 Apr;26(3):194-200. doi: 10.1002/bem.20064.
Steadily growing use of electromagnetic fields, especially in conjunction with wireless communication systems, has led to increasing public concern about possible health effects of electromagnetic radiation. However, besides the well-known thermal effect of electromagnetic fields on biological tissue, there is no clear evidence of further athermal interaction mechanisms with biological systems. The present study was designed to determine the changes in bilayer permeability in egg lecithin multilamellar vesicles after exposure to 900 MHz microwave radiation for a period of 5 h. Specific absorption rate (SAR) of the radiation for the investigated liposome sample was found to be 12 +/- 1 W/kg. Liposomal changes in permeability were monitored using a light scattering technique. Optical anisotropy of the liposome sample decreased dramatically upon exposure to microwave radiation, indicating structural changes in acyl chain packing. IR and NMR ((1)H NMR) studies, which have been employed to reveal structural alterations in microwave, exposed vesicles showed an increased damage upon exposure to microwave. The changes observed in the (1)H NMR spectrum of the microwave exposed sample indicated hydrolysis of carboxylic and phosphoric esters. IR study showed conformational changes in the acyl chains of the lipids upon microwave exposure. However, both IR and (31)P NMR did not show any appreciable changes in the head group part of the lipids.
电磁场的使用稳步增长，尤其是与无线通信系统结合使用时，这引发了公众对电磁辐射可能对健康产生影响的日益关注。然而，除了电磁场对生物组织的众所周知的热效应外，没有明确证据表明存在与生物系统的进一步非热相互作用机制。本研究旨在确定卵卵磷脂多层囊泡在暴露于900 MHz微波辐射5小时后的双层渗透率变化。发现所研究脂质体样品的辐射比吸收率（SAR）为12±1 W/kg。使用光散射技术监测脂质体渗透率的变化。脂质体样品在暴露于微波辐射后，其光学各向异性显著降低，表明酰基链堆积发生了结构变化。用于揭示微波暴露囊泡结构改变的红外光谱（IR）和核磁共振（（1）H NMR）研究表明，暴露于微波后损伤增加。微波暴露样品的（1）H NMR光谱中观察到的变化表明羧酸酯和磷酸酯发生了水解。红外光谱研究表明，微波暴露后脂质的酰基链发生了构象变化。然而，红外光谱和（31）P NMR均未显示脂质头部基团部分有任何明显变化。
