Oliveira Ribeiro C A, Filipak Neto F, Mela M, Silva P H, Randi M A F, Rabitto I S, Alves Costa J R M, Pelletier E
Departamento de Biologia Celular, Universidade Federal do Paraná, CP. 19031, CEP: 81.531-990 Curitiba, PR, Brazil.
Environ Res. 2006 May;101(1):74-80. doi: 10.1016/j.envres.2005.11.005. Epub 2006 Jan 4.
Hematological indices are gaining general acceptance as valuable tools in monitoring various aspects the health of fish exposed to contaminants. In this work some effects of methyl mercury (MeHg), inorganic lead (Pb2+), and tributyltin (TBT) in a tropical fish species were evaluated by hematological methods after a trophic exposition at a subchronic level. Forty-two mature individuals of the freshwater top predator fish Hoplias malabaricus were exposed to trophic doses (each 5 days) of MeHg (0.075 microg g(-1)), Pb2+ (21 microg g(-1)), and TBT (0.3 microg g(-1)) using young fish Astyanax sp. as prey vehicle. After 14 successive doses over 70 days, blood was sampled from exposed and control groups to evaluate hematological effects of metals on erythrocytes, total leukocytes and differential leukocytes counts, hematocrit, hemoglobin concentration, and red blood cell indices mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). Transmission electron microscopy and image analysis of erythrocytes were also used to investigate some morphometric parameters. Results show no significant effects in MCH and MCHC for all tested metals, but differences were found in erythrocytes, hemoglobin, hematocrit, MCV, and white blood cells counts. The number of leukocytes was increased in the presence of MeHg, suggesting effects on the immune system. Also the MCV increased in individuals exposed to MeHg. No ultrastructural damages were observed in red blood cells but the image analysis using light microscopy revealed differences in area, elongation, and roundness of erythrocytes from individuals exposed to Pb2+ and TBT but not in the group exposed to MeHg. The present work shows that changes in hematological and blood indices could highlight some barely detectable metal effects in fish after laboratory exposure to contaminated food, but their application in field biomonitoring using H. malabaricus will need more detailed studies and a careful consideration of environmental parameters.
血液学指标作为监测接触污染物鱼类健康各个方面的有价值工具正逐渐得到广泛认可。在这项工作中，通过亚慢性水平的营养暴露后，采用血液学方法评估了甲基汞（MeHg）、无机铅（Pb2+）和三丁基锡（TBT）对一种热带鱼类的一些影响。42条淡水顶级捕食性鱼类马拉巴丽鱼（Hoplias malabaricus）的成熟个体，以幼鱼丽脂鲤属（Astyanax sp.）作为猎物载体，接受了营养剂量（每5天一次）的MeHg（0.075微克/克(-1)）、Pb2+（21微克/克(-1)）和TBT（0.3微克/克(-1)）。在70天内连续给药14次后，从暴露组和对照组采集血液，以评估金属对红细胞、总白细胞和分类白细胞计数、血细胞比容、血红蛋白浓度以及红细胞指数平均红细胞体积（MCV）、平均红细胞血红蛋白含量（MCH）和平均红细胞血红蛋白浓度（MCHC）的血液学影响。还利用透射电子显微镜和红细胞图像分析来研究一些形态学参数。结果表明，所有受试金属对MCH和MCHC均无显著影响，但在红细胞、血红蛋白、血细胞比容、MCV和白细胞计数方面存在差异。在MeHg存在的情况下白细胞数量增加，表明对免疫系统有影响。暴露于MeHg的个体中MCV也增加。红细胞未观察到超微结构损伤，但使用光学显微镜的图像分析显示，暴露于Pb2+和TBT的个体红细胞在面积、伸长率和圆度方面存在差异，而暴露于MeHg的组则没有。目前的研究表明，血液学和血液指标的变化可以突出实验室暴露于受污染食物后鱼类中一些难以检测到的金属影响，但将其应用于使用马拉巴丽鱼进行的现场生物监测还需要更详细的研究，并仔细考虑环境参数。
