Role of eicosanoids in gastric mucosal protection and damage

目的：微管系统在细胞结构和功能中发挥重要作用，包括细胞内转运、细胞分裂、运动和分化。本研究的目的是观察秋水仙碱(CC；抑制微管形成的药物)对乙醇损伤大鼠胃细胞的作用及其对细胞内钙离子通量的影响。方法：分离雄性Wistar大鼠胃细胞，按Terano‘s方法进行培养。1)用~(51)铬释放法检测乙醇对细胞损伤的剂量和时间依赖性。2)为了评价CC对细胞损伤的影响，将细胞在单独含氧或含10^&lt；-7；-10；-5&gt；的单独含氧培养液或含10^&lt；-7&gt；-10^&gt；-5&gt；的含10^&lt；-7&gt；-5&gt；的培养液中预先孵育30分钟，在37ﾟ℃下不加或不加Ca^&lt；细胞与8%乙醇孵育60min，测定铬释放量。3)用单独或含CC的培养液预先孵育30min后，测定细胞内流。4)用预先标记的细胞在单独或含CC的培养液中孵育30min，测定Ca~(2+)外流。结果：乙醇以剂量和时间相关的方式引起细胞损伤。因此，在接下来的实验中，我们选择了暴露在80%乙醇中60min的方法来诱导细胞损伤。单独的CC对铬的释放没有影响，但增加了10^&lt；-5&gt；M的乙醇伤害，这种影响仅在含钙的培养液中才能看到(表)。CC不影响Ca^&lt；2+-内流，但减少了Ca^&lt；2+-外流。无钙生理盐水+8%乙醇6 11*2 27*4 29*3 CC+8%乙醇6 13*4 38*4 48*6 P值NS&lt；0.01&lt；0.01结论：微管对培养的大鼠胃细胞钙外流有调节作用。乙醇对细胞的损伤是通过损伤微管和CC，可能是通过减少Ca^&lt；2+和gt；-外流，从而增加细胞内游离钙而加重的。

Aim: Microtubular system plays an important role in cell structure and functions including intracellular transport, cell division, movement, and differentiation. The aims of this study were to assess effects of colchicine (CC; drug which inhibits microtubular formation) on ethanol injury and Ca^<2+>-fluxes in cultured rat gastric cells. Methods: Gastric cells were isolated from male Wistar rats and cultured according to Terano's method. 1) Dose- and time-dependency of cell injury by ethanol were assessed with ^<51>Cr-release. 2) To assess effect of CC on cell injury, the cells were pre-incubated in oxygenated medium alone or medium containing 10^<-7>-10^<-5> in oxygenated medium alone or medium containing 10^<-7>-10^<-5> M CC for 30 min at 37ﾟC in the absence or presence of Ca^<2+>. Then cells were incubated with 8% ethanol for 60 min and ^<51>Cr-release was measured. 3) ^<45>Ca^<2+>-influx was assessed in the cells pre-incubated with medium alone or medium containing CC for 30 min. 4) Ca^<2+>-efflux was measured by incubating the pre-labeled cells with ^<45>CaCl_2 in medium alone or medium containing CC for 30 min. Results: Ethanol caused cell injury in dose- and time- related ways. So, 60-min exposure to 80% ethanol was chosen to induce cell injury in the following experiments. Cc alone did not affect ^<51>Cr-release, but increased ethanol injury at the concentration of 10^<-5> M. This effect was seen only in Ca^<2+>-containing medium (Table). CC did not affect Ca^<2+>-influx but reduced Ca^<2+>-efflux.Specific ^<51>Cr-release (%) Ca^<2+> conc. in medium n Ca-free 1.3 mM 3.9 mM Saline + 8% ethanol 6 11 * 2 27 * 4 29 * 3 CC + 8% etanol 6 13 * 4 38 * 4 48 * 6 P-value NS < 0.01 < 0.01 Conclusion: Microtubules may modulate Ca^<2+>-efflux from cultured rat gastric cells. Ethanol injury to the cells is aggravated by impairment of microtubules with CC possibly via decrease in Ca^<2+>-efflux, and resultant increase in cytosolic free calcium.