Chang Chin-Chyuan, Lee Pai-Po, Liu Chun Hung, Cheng Winton
Institute of Tropical Agriculture, National Pingtung University of Science and Technology, Pingtung 912, Taiwan, ROC.
Fish Shellfish Immunol. 2006 Apr;20(4):574-85. doi: 10.1016/j.fsi.2005.06.012. Epub 2005 Oct 10.
The total haemocyte count (THC), phenoloxidase activity, respiratory bursts (release of superoxide anions), superoxide dismutase (SOD) activity, and phagocytic activity and clearance efficiency to the pathogen Lactococcus garvieae were measured when freshwater giant prawns Macrobrachium rosenbergii (18.2+/-2.1 g) were individually reared in water containing concentrations of trichlorfon of 0, 0.2, or 0.4 mg L(-1) for a 144-h period. No significant differences in the THC were observed among prawns at the beginning and following 144 h of exposure to 0, 0.2, and 0.4 mg L(-1) trichlorfon. However, phenoloxidase activity significantly decreased when the prawns were exposed to trichlorfon at 0.2 and 0.4 mg L(-1), and no significant differences were observed between the two concentrations at any sampling time. The total production of superoxide anion by M. rosenbergii significantly increased with exposure to 0.2 and 0.4 mg L(-1) trichlorfon, and no significant differences were observed between the two concentrations during the 144-h exposure period. However, M. rosenbergii exposed to 0.2 and 0.4 mg L(-1) trichlorfon showed decreased SOD activity from 48 to 144 h. Phagocytic activity and clearance efficiency to L. garvieae significantly decreased when prawns were exposed to 0.2 and 0.4 mg L(-1) trichlorfon for 48 h. In another experiment, prawns were challenged with 5 x 10(5) colony-forming units (cfu)prawn(-1) of L. garvieae, then reared in water containing different concentrations of trichlorfon. The onset of mortality was earlier in prawns exposed to trichlorfon compared to those exposed to the zero control. The cumulative mortality of prawns directly increased with ambient trichlorfon concentrations in the range of 0-0.4 mg L(-1) after 168 h. It is concluded that exposure of M. rosenbergii to trichlorfon at 0.2 mg L(-1) or more caused cytotoxicity resulting in depression of the immune response, and increased its susceptibility to L. garvieae infection.
将罗氏沼虾（18.2±2.1克）分别置于含0、0.2或0.4毫克/升敌百虫的水中饲养144小时，期间测定其总血细胞计数（THC）、酚氧化酶活性、呼吸爆发（超氧阴离子释放）、超氧化物歧化酶（SOD）活性，以及对病原菌格氏乳球菌的吞噬活性和清除效率。在暴露于0、0.2和0.4毫克/升敌百虫144小时的开始和结束时，未观察到虾的总血细胞计数有显著差异。然而，当虾暴露于0.2和0.4毫克/升敌百虫时，酚氧化酶活性显著降低，且在任何采样时间，这两个浓度之间均未观察到显著差异。罗氏沼虾超氧阴离子的总产生量随暴露于0.2和0.4毫克/升敌百虫而显著增加，且在144小时暴露期内，这两个浓度之间未观察到显著差异。然而，暴露于0.2和0.4毫克/升敌百虫的罗氏沼虾在48至144小时显示出SOD活性降低。当虾暴露于0.2和0.4毫克/升敌百虫48小时时，对格氏乳球菌的吞噬活性和清除效率显著降低。在另一项实验中，用5×10⁵菌落形成单位（cfu）/虾的格氏乳球菌对虾进行攻毒，然后将其饲养在含不同浓度敌百虫的水中。与暴露于零对照的虾相比，暴露于敌百虫的虾死亡开始时间更早。168小时后，虾的累积死亡率随环境敌百虫浓度在0 - 0.4毫克/升范围内直接增加。得出结论，罗氏沼虾暴露于0.2毫克/升或更高浓度的敌百虫会导致细胞毒性，从而导致免疫反应受到抑制，并增加其对格氏乳球菌感染的易感性。
