胃液中微量元素與丙二醛之分析研究

Study of Trace Elements and Malondialdehyde in Gastric Juice

江偉誌(Wei-Chih Chiang)

指導教授 ： 黃友利

高雄醫學大學/健康科學院/醫學檢驗生物技術學研究所/碩士(2014年)

摘要

微量元素在維持人體正常生理機能上扮演重要角色，但是過量攝取或暴露於有害元素中皆會造成人體負面的影響，脂質過氧化作用則為各類疾病可能的致病機轉之一。在台灣，腸胃疾患相當普遍，包括胃癌與胃幽門螺旋桿菌感染等。鑒於在人體消化過程中，胃液扮演關鍵的角色，本研究乃針對人類胃液中的微量元素與脂質過氧化作用產物-丙二醛進行分析，並進而探究與疾病間的相關性。基於胃液基質的複雜性與其中微量元素含量較低，本研究利用微波輔助消化技術配合感應耦合電漿質譜儀的同時多元素與高靈敏度分析特性，進行人類胃液中多重微量元素(鉻、錳、銅、鋅、鍶及鉛)的分析方法開發。研究中針對主要影響分析結果的參數包含消化液組成、消化條件、升溫及持溫時間與碰撞反應氣體流速進行最適化的探討。此外，胃部疾患胃液中脂質過氧化作用產物分析，則利用高效能液相層析法進行胃液中丙二醛的檢測。研究結果顯示，在最適化的條件下，待測元素(鉻、錳、銅、鋅、鍶及鉛)的線性範圍為0.5–10 μg/L，線性相關係數皆大於0.995；精密度介於1.7–11.0 %；添加回收率介於87–109 %；方法偵測極限分別為0.02, 0.01, 0.02, 0.03, 0.01及0.01 ng/g，顯示本方法的分析可靠性。本方法也實際應用於胃炎、胃瘜肉、十二指腸潰瘍、食道炎、巴特氏食道症、胃潰瘍及胃癌患者胃液中鉻、錳、銅、鋅、鍶及鉛的分析。針對胃液中丙二醛的分析結果顯示，在慢性胃炎者中受胃幽門螺旋桿菌感染者的胃液中丙二醛含量顯著地高於未感染者(p < 0.0001)；胃腸上皮化生者的胃液丙二醛含量顯著地高於慢性胃炎者(p < 0.0001)；胃癌經手術治療後者之胃液丙二醛含量顯著地高於慢性胃炎者(p < 0.0001)，但並未顯著高於胃腸上皮化生者(p = 0.566)。本研究開發完成利用微波輔助消化技術配合感應耦合電漿質譜儀進行胃液中微量元素的分析方法並發現胃幽門螺旋桿菌感染以及胃部疾病的病程發展與胃液中丙二醛具有相關性。

關鍵字

胃液 ； 微量元素 ； 丙二醛 ； 脂質過氧化作用 ； 感應耦合電漿質譜法

並列摘要

Trace elements play important roles in maintaining physiological functions in the human body, where both the excessive intake of and exposure to harmful elements have negative effects. Previous studies proposed that lipid peroxidation is a risk factor for various diseases. Gastric cancer is the most common cancer in Taiwan and is caused by smoking, drinking, excessive intake of nitrite, and Helicobacter pylori infection. Gastric juice plays an important role in the digestion of food in humans. In this study, we analyzed trace elements and a lipid peroxidation marker (MDA) in gastric juice and explored the correlation between diseases. Due to the complex matrix composition of gastric juice and extremely low content of trace elements, we developed a method using microwave digestion coupled with inductively coupled plasma mass spectrometry (ICP-MS) for the determination of trace Cr, Mn, Cu, Zn, Sr and Pb in human gastric juice. We investigated the effects of several parameters on system performance such as the composition of sample digests, digestion temperatures, and digestion ramp and hold times. The flow rate of the collision cell gas used to reduce polyatomic interferences in ICP-MS was also investigated. In addition, MDA levels in gastric juice were measured using high performance liquid chromatography. Under the optimized conditions, the linearity, detection limits, and accuracies of the proposed method were evaluated. Linear ranges of the six elements ranged from 0.5-10 μg/L, with coefficients of determination that were greater than 0.995. The detection limits of Cr, Mn, Cu, Zn, Sr, and Pb were 0.02, 0.01, 0.02, 0.03, 0.01, and 0.01 ng/g, respectively. The precision values of the six elements ranged from 1.7 %- 11.0 %. The accuracy of the method was evaluated using spike recoveries for the six analytes and was satisfactory (87 % - 109 %). We applied our method to the determination of Cr, Mn, Cu, Zn, Sr and Pb in clinical gastric juice samples from patients with different diseases including gastritis, gastric polyps, duodenal ulcers, esophagitis, Barrett's esophagus, and gastric ulcers. The result of MDA levels in gastric juice show that MDA levels of H. pylori-positive patients were significantly higher than those of H. pylori-negative patients with chronic gastritis (p < 0.0001). MDA in gastric juice was much higher in patients with gastric intestinal metaplasia and gastric cancer post-surgical resection (both p < 0.0001) compared to those in patients with chronic gastritis. However, there were no significant differences between MDA levels between patients in the gastric intestinal metaplasia and gastric cancer post-surgical resection groups (p = 0.566). In this study, a method for microwave digestion coupled with ICP-MS was successfully developed for determination of trace elements in gastric juice, and demonstrated that MDA levels in gastric juice are dependent on disease activity and Helicobacter pylori infection.

並列關鍵字

Gastric juice ； Trace element ； Malondialdehyde ； Lipid peroxidation ； ICP-MS

參考文獻

1. Kelley, J. R.; Duggan, J. M., Gastric cancer epidemiology and risk factors. J. Clin. Epidemiol. 2003, 56 (1), 1-9.

2. Franceschi, S.; Lavecchia, C., Alcohol and the Risk of Cancers of the Stomach and Colon-Rectum. Digest. Dis. 1994, 12 (5), 276-289.

3. Buiatti, E.; Palli, D.; Decarli, A.; Amadori, D.; Avellini, C.; Bianchi, S.; Bonaguri, C.; Cipriani, F.; Cocco, P.; Giacosa, A.; Marubini, E.; Minacci, C.; Puntoni, R.; Russo, A.; Vindigni, C.; Fraumeni, J. F.; Blot, W. J., A Case-Control Study of Gastric-Cancer and Diet in Italy .2. Association with Nutrients. Int. J. Cancer 1990, 45 (5), 896-901.

4. Joossens, J. V.; Hill, M. J.; Elliott, P.; Stamler, R.; Stamler, J.; Lesaffre, E.; Dyer, A.; Nichols, R.; Kesteloot, H., Dietary salt, nitrate and stomach cancer mortality in 24 countries. Int. J. Epidemiol. 1996, 25 (3), 494-504.

5. Howson, C. P.; Hiyama, T.; Wynder, E. L., The Decline in Gastric-Cancer - Epidemiology of an Unplanned Triumph. Epidemiol. Rev. 1986, 8, 1-27.