Russo J, Lagadic L
CNRS, UMR 6553 ECOBIO, Université de Rennes, France.
Cell Biol Toxicol. 2000;16(1):15-30. doi: 10.1023/a:1007640519746.
Morphological characteristics and functions of hemocytes were used to compare the immunological effects of biological and chemical stress in the freshwater snail Lymnaea palustris. Animals were either infected by a trematode parasite (Metaleptocephalus sp.), or exposed to environmental contaminants, namely atrazine and hexachlorobenzene (HCB). Three populations of circulating hemocytes, morphologically and cytochemically distinct (round cells, hyalinocytes, granulocytes), were identified in both control and parasitized or pesticide-exposed snails. After 6 h of exposure, HCB and atrazine resulted in 8-fold increases in the mean total number of hemocytes, whereas only a 2.2-fold increase was observed 6 h after cercaria emission in parasitized snails. The impact of HCB was limited to the first 24 h of exposure, whereas long-lasting effects of atrazine were observed. Hyalinocytes and, to a lesser extent, round cells contributed most to the increases in hemocyte density in pesticide-exposed snails. Parasitism and atrazine treatment resulted in significant increases of lectin-stained hemocytes, whereas exposure to HCB did not affect the percentages of stained and unstained cells. Hemocyte phagocytic activity increased in HCB-exposed snails but with no concomitant change of the oxidative burst. Opposite results were obtained in atrazine-treated snail hemocytes, with unchanged phagocytosis and decreased phorbol 12-myristate 13-acetate-stimulated production of reactive oxygen intermediates. No increase in phagocytosis, or in the production of reactive oxygen intermediates, was observed in hemocytes from parasitized snails. Infection with the immunologically compatible trematode parasite Metaleptocephalus sp. and exposure to atrazine generated similar reactions from circulating hemocytes, whereas a different response pattern was observed in HCB-exposed snails.
利用血细胞的形态特征和功能，比较生物应激和化学应激对淡水螺类——静水椎实螺（Lymnaea palustris）免疫的影响。实验动物分别感染了吸虫寄生虫（Metaleptocephalus sp.），或暴露于环境污染物，即莠去津和六氯苯（HCB）中。在对照、感染寄生虫或暴露于农药的蜗牛中，均鉴定出三类循环血细胞，它们在形态学和细胞化学上存在差异（圆形细胞、透明细胞、粒细胞）。暴露6小时后，HCB和莠去津使血细胞平均总数增加了8倍，而感染寄生虫的蜗牛在尾蚴逸出6小时后，血细胞总数仅增加了2.2倍。HCB的影响仅限于暴露的前24小时，而莠去津则具有持久的影响。在暴露于农药的蜗牛中，透明细胞以及在较小程度上的圆形细胞，对血细胞密度的增加贡献最大。寄生虫感染和莠去津处理导致凝集素染色的血细胞显著增加，而暴露于HCB对染色和未染色细胞的百分比没有影响。暴露于HCB的蜗牛中，血细胞吞噬活性增加，但氧化爆发没有相应变化。在莠去津处理的蜗牛血细胞中，得到了相反的结果，吞噬作用未改变，佛波酯12 - 肉豆蔻酸酯13 - 乙酸酯刺激的活性氧中间体产生减少。在感染寄生虫的蜗牛血细胞中，未观察到吞噬作用或活性氧中间体产生的增加。感染免疫相容性吸虫寄生虫Metaleptocephalus sp.和暴露于莠去津，使循环血细胞产生了相似的反应，而在暴露于HCB的蜗牛中观察到了不同的反应模式。
