Objective To know the situation of the water environment in the Eling Lake Area and provide the theoretical basis for protecting the biosystem of this area. Methods The water samples were collected from the sites 0.5 meters below the water surface of input and output water area, the water area near the east and west bank of the Eling Lake, the center of the lake, and also from the sites 0.5 meters above the bottom of the lake .The water sampling was carried out in August 2005, October 2005 and May 2006. Country standard method was used to determine the physical and chemical characteristics of water samples. The sampling, determination and evaluation in the investigation were according to related standard regulations. Results The water temperature was 5.6 ℃, pH value was 8.49, the total amount of Ca2+ and Mg2+, suspended matter, chlorides, sulfate, DO, COD, BOD5, Cu2+ and Zn2+ were 95.4 mg/L, 87.0 mg/L, 45.0 mg/L, 80.0 mg/L, 7.1mg/L, 11.0 mg/L, 2.0 mg/L, 0.002 mg/L and 0.009 mg/L respectively. Conclusion All of the physical and chemical characteristics of the water samples meet the water quality criterion of the class ruled by GB 3838-2002, and the water can be used as source water.

[摘 要] 目的：探讨甲硫氨酸限制对肺腺癌（LUAD）细胞增殖、凋亡及磷酸戊糖途径的影响。方法：将H1299、A549细胞分为Met+组和Met−组，分别用含100 μmol/L或不含甲硫氨酸的培养基连续培养4 d，采用细胞计数法评估甲硫氨酸处理对H1299和A549细胞增殖的影响，PI染色法检测细胞周期分布，Annexin Ⅴ-PE/7AAD标记细胞凋亡，利用DCFH-DA探针检测细胞内ROS水平，WST-8法和DTNB法分别测定细胞内NADPH与GSH含量；通过癌症基因组图谱（TCGA）数据库分析葡萄糖-6-磷酸脱氢酶（G6PD）和6-磷酸葡萄糖酸脱氢酶（6PGD）表达与甲硫氨酸代谢通路的关系；采用WB法检测甲硫氨酸处理及回补甲硫氨酸下游代谢产物S-腺苷甲硫氨酸（SAM）对LUAD细胞中磷酸戊糖途径关键酶G6PD和6PGD表达的影响。结果：甲硫氨酸限制显著抑制H1299和A549细胞增殖（均P < 0.01），将细胞周期阻滞于G2/M期（均P < 0.05），显著升高细胞内总ROS水平（均P < 0.001）并促进细胞凋亡（均P < 0.001）；同时，甲硫氨酸限制显著降低了细胞内NADPH和GSH水平（均P < 0.01），抑制DNA合成（均P < 0.01）。分析TCAG数据发现，G6PD和6PGD表达水平与甲硫氨酸代谢通路呈正相关（均P < 0.001），甲硫氨酸限制下调G6PD和6PGD蛋白表达（均P < 0.01），而回补SAM可部分逆转甲硫氨酸限制对G6PD和6PGD的表达的抑制（均P < 0.01），提示甲硫氨酸通过SAM合成调控磷酸戊糖途径。结论：甲硫氨酸限制通过抑制磷酸戊糖途径抑制LUAD细胞增殖，为甲硫氨酸限制疗法治疗LUAD提供实验依据。