|Abstract: ||本論文研究目的在於探討分別以添加 1 mg/kg、5 mg/kg 甲基汞、無機汞飼料投餵點帶石斑魚 (Epinephelus coioides)，對點帶石斑魚排泄物與肌肉、肝臟、魚皮、胃、腸、鰓絲、腎臟、脾臟、血液、腦、心臟等組織，總汞、甲基汞蓄積與排除之影響。結果顯示，無機汞處理組除了在腸、腎、鰓絲等組織總汞蓄積濃度顯著高於控制組外，其餘各組織與控制組並無顯著差異，且可於排泄物中發現大量的總汞及些許甲基汞的存在；甲基汞處理組在所有分析組織中總汞、甲基汞濃度皆顯著高於控制組，且可於排泄物偵測到總汞、甲基汞的存在；排除實驗中發現，若是甲基汞在肌肉、腦等組織蓄積將不易被排除，而在其他組織如腎、肝、鰓等組織改投餵控制組飼料 7 天後組織內甲基汞濃度則大幅下降；5 mg/kg 甲基汞處理組中，蓄積實驗最終日各組織甲基汞蓄積濃度依序為腎 (1856.67 μg/kg)>腸 (1383.33 μg/kg)>肝 (1176.67 μg/kg)>心 (883.00μg/kg)>胃 (723.33 μg/kg)>脾 (685.33 μg/kg)>腦 (528.00 μg/kg)>肌肉(392.67 μg/kg)>鰓 (367.00 μg/kg)>魚皮(194.67 μg/kg)，且發現若以 1 mg/kg 甲基汞飼料投餵點帶石斑魚 7 天，組織吸收約 50 % 總投餵甲基汞量，以 5 mg/kg 甲基汞飼料投餵點帶石斑魚 7 天，組織約吸收 30 % 總投餵甲基汞量，其中皆以肌肉、肝臟為主要蓄積組織；實驗期間所有組別，其肌肉、肝臟、胃、魚皮組織藉由總汞、甲基汞檢驗發現，甲基汞處理組的總汞、甲基汞濃度均顯著高於控制組與無機汞處理組，並發現肌肉、肝臟、胃、腸、魚皮組織中甲基汞分別佔總汞含量的 63.88 % - 89.84 %、63.97 % - 90.27 %、7.62 % - 88.63 %、1.71 % - 95.77 %、27.46 % - 97.72 %。|
The objective of this study is to investigate the accumulation and elimination of methylmercury and inorganic mercury in different tissues including feces, muscle, liver, skin, stomach, intestine, gill filament, kidney, spleen, blood, brain and heart in Orange-spotted Grouper (Epinephelus coioides) after oral administration at concentration of 1 mg/kg and 5 mg/kg for methylmercury and inorganic mercury. The results showed that in inorganic mercury treatment group, except for intestine, kidney and gill filament tissues which showed significantly higer total mercury concentrations, there is no significant difference between the concentrations of total mercury in other tissues and the control group. In addition considerable amount of total mercury and some methylmercury were detected in feces. In methylmercury treatment group, the concentrations of total mercury and methylmercury in tissues were significantly higher than that in the control group; and total mercury and methylmercury can be detected in the feces. For elimination study, methylmercury that accumulated in muscle and brain can hardly be eliminated. However, the concentrations of methylmercury in other tissues such as kidney, liver and gill filament decreased rapidly 7 days post oral administration. In 5 mg/kg methylmercury treatment group, methylmercury was accumulated in tissues in the order of kidney (1856.67 μg/kg)> intestine (1383.33 μg/kg)> liver (1176.67 μg/kg)> heart (883.00μg/kg)> stomach (723.33 μg/kg)> spleen (685.33 μg/kg)> brain (528.00 μg/kg)> muscle (392.67 μg/kg)> gill filament (367.00 μg/kg)> skin (194.67 μg/kg) referring to its concentration. After 7 days oral administration of 1 mg/kg and 5 mg/kg methylmercury, the absorption of methylmercury in tissues were approximately 50 % and 30 %, respectively. In the methylmercury treatment group, the concentrations of total mercury and methylmercury in muscle, liver, stomach and skin were significantly higher than that in control group and inorganic mercury treatment group. The percentages of methylmercury in the total mercury for muscle, liver, stomach, intestine and skin were found to be in the range of 63.88 % - 89.84 %, 63.97 % - 90.27 %, 7.62 % - 88.63 %, 1.71 % - 95.77 %, 27.46 % - 97.72 %, respectively.