放射损伤、烧伤与放烧复合伤血清成份对心肌细胞钙离子通道活动的影响

本实验研究了放射损伤、烧伤与放烧复合伤后血清成份对培养心肌细胞Ｌ－型钙离子通道活动的影响，结果表明：伤后血清对上述通道均有激活作用，从而改变细胞内钙离子水平，此可能为伤后心脏功能抑制的一个重要机理。在作用强度上，复合伤血清重于单一伤、烧伤重于放射损伤，这是导致不同伤后血清对心功能抑制程度不一的重要因素。对伤后血清成分作用的进一步研究表明：伤后血清大分子的作用不明显，主要是血清低分子与血清脂质起作用。其中，放烧复合伤血清低分子不仅使通道开放增加，还使膜片噪声增加，提示其作用包括改变其Ｌ－型钙离子通道活动与改变膜的物理特性二个方面，它们共同导致细胞的功能变化；血清脂质对钙通道的作用可被ＳＯＤ所抑制，表明其作用与氧自由基反应有关。至于伤后血清低分子与血清脂质中的具体毒性成分以及它们对Ｌ－型钙离子通道影响的调控机制，有待于进一步研究

EFFECTS OF DIFFERENT COMPONENTS OF SERUM FROM RADIATION,BURN AND COMBINED RADIATION BURN INJURY ON L TYPE CALCIUM CHANNEL OF CULTURED MYOCARDIAL CELLS

The effects of different components of serum from radiation, burn and combined radiation burn injury on the activity of L type calcium channel in cultured myocardial cells were investigated in this study. The results revealed that the serum from different injury groups could all activate the L type calcium channel of cultured myocardial cells. These changes altered the calcium level in cells, which might be an important cause of dysfunction in cardiovascular system. Among the components of postinjury serum, the effect of high molecular components (>8-10kD) was not significant ,whereas low molecule (<8-10kD) and lipid components were the major effective components. The low molecule of postinjury serum affected not only on the opening activity of L type channel, but also on the state of molecular movement in the membrane. The effect of serum lipids from injury groups could be depressed by SOD, which suggests that there may be free radical reactions during the serum lipids effect on calcium channel.The effects of serum and its components from combined radiation burn group were the most intensive, and those from radiation injury were the weakest. The nature of the toxic material in serum remains to be further investigated.