Aggarwal Manoj, Naraharisetti Suresh Babu, Dandapat S, Degen G H, Malik J K
National Referral Laboratory (Chemical Residues), Division of Pharmacology and Toxicology, Indian Veterinary Research Institute, Izatnagar UP, India.
Toxicology. 2008 Sep 29;251(1-3):51-60. doi: 10.1016/j.tox.2008.07.050. Epub 2008 Jul 23.
The metalloid arsenic and the chlorinated insecticide endosulfan are common environmental contaminants. Humans, animals, and birds are exposed to these chemicals through water and food. Although health effects due to either arsenic or endosulfan exposure are documented, the toxicological impact of co-exposure to these environmental pollutants is unpredictable and unknown. The present study was undertaken to assess whether concurrent exposure to arsenic and endosulfan induces significant alterations in immunological functions. Day-old chicks were exposed to 3.7 ppm of arsenic via drinking water and to 30 ppm of endosulfan-mixed feed either individually or concurrently for up to 60 days. All the chicks were vaccinated with Ranikhet disease virus (F-strain; RD-F) on days 1 and 30. During the course of study and at term, parameters of cellular and humoral immunity were determined. None of the treatments altered the absolute body weight or body weight gain, except arsenic significantly reduced weight gain on day 60. Absolute, but not the relative, weights of spleen, thymus and bursa of Fabricius were significantly reduced in all the treatment groups. The metalloid and insecticide combination significantly depressed the ability of peripheral blood and splenic lymphocytes to proliferate in response to antigen RD-F and mitogen Con A. The delayed type hypersensitivity response to 2,4-dinitro-1-chlorobenzene or to PHA-P was also significantly decreased. Nitric oxide production by RD-F or lipopolysaccharide-stimulated peripheral blood and splenic mononuclear cells was significantly suppressed following concurrent exposure to arsenic and endosulfan. Furthermore, the combined exposure also decreased the antibody response to RD-F. The suppression of cellular and humoral immune responses was also evident following administration of individual compounds, and it was not exacerbated following concurrent exposure. To our knowledge, this is the first report describing the suppression of immune responses following exposure to arsenic alone or in combination with endosulfan at environmentally realistic concentrations in avian species. Therefore, immunotoxicological effects induced by concurrent exposure to arsenic and chlorinated pesticides should be considered when assessing the risk to human and animal health.
类金属砷和有机氯杀虫剂硫丹是常见的环境污染物。人类、动物和鸟类通过水和食物接触这些化学物质。尽管已有文献记载砷或硫丹暴露对健康的影响，但同时暴露于这些环境污染物的毒理学影响却不可预测且未知。本研究旨在评估同时暴露于砷和硫丹是否会引起免疫功能的显著改变。将一日龄雏鸡通过饮用水暴露于3.7 ppm的砷，并通过单独或同时暴露于30 ppm硫丹混合饲料中，持续60天。所有雏鸡在第1天和第30天用新城疫病毒（F株；RD-F）进行疫苗接种。在研究过程中和实验结束时，测定细胞免疫和体液免疫参数。除砷在第60天显著降低体重增加外，其他处理均未改变绝对体重或体重增加。所有处理组的脾脏、胸腺和法氏囊的绝对重量（而非相对重量）均显著降低。类金属与杀虫剂的组合显著抑制外周血和脾淋巴细胞对抗原RD-F和丝裂原Con A的增殖能力。对2,4-二硝基-1-氯苯或PHA-P的迟发型超敏反应也显著降低。同时暴露于砷和硫丹后，RD-F或脂多糖刺激的外周血和脾单核细胞产生的一氧化氮显著受到抑制。此外，联合暴露还降低了对RD-F的抗体反应。单独给予化合物后，细胞免疫和体液免疫反应的抑制也很明显，同时暴露后并未加剧。据我们所知，这是第一份描述在鸟类中以环境现实浓度单独或与硫丹联合暴露于砷后免疫反应受到抑制的报告。因此，在评估对人类和动物健康的风险时，应考虑同时暴露于砷和氯化农药所诱导的免疫毒理学效应。
