Role of eicosanoids in gastric mucosal protection and damage

目的：微管系统在细胞内运输、细胞分裂、运动和分化等细胞结构和功能中起着重要作用。本研究旨在探讨秋水仙碱（CC；抑制微管形成的药物）对乙醇损伤大鼠胃细胞和Ca^<2+>-通量的影响。方法：从雄性Wistar大鼠中分离胃细胞，按Terano法培养。1)以^<51> cr释放量评估乙醇对细胞损伤的剂量依赖性和时间依赖性。2)为了评估CC对细胞损伤的影响，将细胞单独在含氧培养基中或含10^<-7>-10^<-5>的培养基中或含10^<-7>-10^<-5> M CC的培养基中预孵育30 min，在37 C的情况下，不含或存在Ca^<2+>。然后用8%乙醇孵育细胞60分钟，测量^<51> cr释放量。3)在单独或含CC的培养基中预孵育30分钟，评估细胞的^<45>Ca^<2+>-内流。4)将预标记细胞与^<45>CaCl_2单独或含CC的培养基中孵育30分钟，测量Ca^<2+>-外排。结果：乙醇对细胞的损伤呈剂量和时间相关。因此，在接下来的实验中，我们选择80%乙醇暴露60分钟来诱导细胞损伤。单独Cc不影响^<51>的cr释放，但增加了浓度为10^<-5> m的乙醇损伤，这种影响仅在含有Ca^<2+>的培养基中可见（表）。CC不影响Ca^<2+>-内流，但减少Ca^<2+>-外排。比比^<51> cr释放（%）Ca^<2+> conc。无Ca 1.3 mM 3.9 mM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 < 0.01 < 0.01结论：微管可调节培养大鼠胃细胞Ca^<2+>-外排。乙醇对细胞的损伤可能通过Ca^<2+>-外排减少，从而导致胞质游离钙增加而加重。

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.