石英对细胞内游离钙.镁的影响

用荧光染料Fura-2测定了家兔肺泡巨噬细胞(AM)和人红细胞(RBC)胞浆游离钙离子浓度(Ca~(2 )]_1),用furaptra测定了AM胞浆游离镁离子浓度(Mg~(2 )]_1)。石英对AM和RBC的毒性导致Ca~(2 )]_1增加,作用时间越长,Ca~(2 )]_1增加越多。同样条件下,染石英尘后的AMMg~(2 )]_1和脂质过氧化物(LPO)值也升高。以上结果提示石英可能破坏了细胞膜的结构和功能,以致细胞外Ca~(2 )和Mg~(2 )内流。卵磷脂、PVPNO和柠檬酸铝可拮抗石英引起的脂质过氧化作用和Ca~2 ]_1及Mg~2 ]_1的增加。卵磷脂有可能用于预防石英粉尘的毒作用。

EFFECT OF QUARTZ ON INTRACELLULAR FREE CALCIUM AND MAGNESIUM

The intracellular free Ca~(2 ) concentration (Ca~(2 )]i) of rabbit alveolar macrophages(AM)and human RBCwas determined with fluorence dye Fura -2.The intracellular free Mg~(2 ) concentration of AM was determined withFuraptra.The toxic effect of quartz on AM and RBC leaded to the increase of Ca~(2 )]i.The longer the time of action,the greater the increase of Ca~(2 )]i.In the same case,Mg~(2 )]i and the LPO values also increased when AMwere exposed to quartz.It is demonstrated that quartz may cause an injury to the structure and function of cellmembrane.As a result,it causes the inner flow of extracellular Ca~(2 ) and Mg~(2 ).Lecithin,PVPNO and aluminum cit-rate can inhibit the lipid peroxidation and the increase of Ca~(2 )]i or Mg~(2 )]i which were induced by quartz.Lecithin may be useful to prevent the toxic effect of quartz.