重金屬對九孔血液細胞的毒性與氧化壓力之研究

Abstract

重金屬鋅、鎘、汞、銅是海洋主要的污染物之一，來源主要是陸地上人類的工業活動，經由雨水沖入河流並匯入海中。因九孔是生活在近海沿岸處的軟體動物，很容易受到重金屬污染而影響其生態及生理。當有重金屬進入九孔血液裡，九孔血液細胞會暴露在重金屬的影響之下而使吞噬及附著能力都降低，進而影響九孔的健康。本篇研究是以九孔血液細胞為研究對象，探討重金屬離子對九孔的毒性及氧化壓力。 結果顯示0.1mM汞離子和1mM銅離子則對九孔的血液細胞的死亡率、附著率及吞噬能力有顯著影響，而鋅離子和鎘離子對血液細胞則無顯著影響。本實驗發現抗氧化劑—100μM維生素E和10mM維生素C維生素可以減輕0.1mM汞離子對細胞的傷害，但銅離子的傷害則無法被減輕，甚至在銅離子濃度超過8mM會與維生素有毒性的加成作用。測量細胞內的脂質過氧化程度則發現1mM汞離子和8mM銅離子都會造成脂質過氧化，而此氧化程度可被維生素所降低。因此汞對九孔血液細胞的傷害，有一部份來自氧化壓力的產生，而推測銅離子對細胞的傷害並非來自氧化壓力，而是有其他機制待深入探究。

Heavy metals, Zn, Cd, Hg and Cu, are the major contaminants in ocean. They are released by industries and then washed by rain and finally flow into ocean. Abalone (Haliotis diversicolor), an economically important mollusc living in coastal waters, have a great possibility to expose on those heavy metals. When heavy metals get into its hemolymph, the physiological hemocytes might be affected. The purpose of this research is to investigate how heavy metals affect hemocytes in abalone. When exposed to heavy metals, 0.01mM Hg(II) and 1mM Cu(II) significantly affected mortality, adhesion and phagocytosis of abalone hemocytes hemocytes, but Zn(II) and Cd(II) didn't. Antioxidants, 10mM vitamin C and 100μM vitamin E can decrease the toxic effects of 0.1mM Hg(II), but not Cu(II). Furthermore, vitamins enhance the toxic effects of 8mM Cu(II). On the other hand, the results of lipid peroxidation showed that 1mM Hg(II) and 8mM Cu(II) increased oxidative stress in abalone hemocytes. Also, lipid peroxidation was decreased when vitamin E or vitamin C presented. The toxic effects of Cu(II) is not only from oxidative stress, and its toxic effects was not overcomed by vitamin C or vitamin E, so this could be investigated in the future.