Dept. of Pharmacology and Toxicology, West Bengal University of Animal and Fishery Sciences, 37 K.B. Sarani, Kolkata 37, India.
Food Chem Toxicol. 2012 Jun;50(6):1946-50. doi: 10.1016/j.fct.2012.03.072. Epub 2012 Apr 1.
Severity of arsenic toxicity was reported to vary depending on its species. The present study reflects the status of different species of arsenic in goat following long-term exposure of arsenic leading to hepatic damage. The experiment was conducted with six black Bengal goats, which were administered with sodium arsenite orally at a dose rate of 2 mgkg(-1) daily for 84 days. Faeces, urine, hair and blood samples were collected from those animals at 14 days interval. Excretion of total arsenic was reduced from 56 days onwards through both faeces and urine indicating higher accumulation of arsenic in body. The speciation study revealed that urinary arsenic was mainly of organic type, whereas hair accumulated almost equal proportion of arsenite, arsenate and organo arsenicals. Goats excreted high proportion of organo arsenicals through faeces possibly due to hepatobiliary secretion of organo arsenic into the gut. Significantly elevated serum alanine aminotransferase and aspartate aminotransferase activities (p<0.05) along with histopathological changes in liver indicated hepatotoxicity. The arsenite fraction increased and organic proportion decreased in urine as the time progressed, which indicates that arsenite gets methylated in liver of goat. The study thus alluded that the toxicity of arsenic would aggravate if the animals were exposed for long time as the hepatotoxicity progressed resulting in decreased methylation and formation of organo arsenicals and decreased excretions through urine.
砷的毒性严重程度据报道取决于其种类。本研究反映了山羊在长期砷暴露导致肝损伤后,体内不同砷种的状况。实验用 6 只孟加拉黑山羊进行,每天口服亚砷酸钠 2mg/kg,持续 84 天。每隔 14 天从这些动物身上采集粪便、尿液、毛发和血液样本。从第 56 天开始,总砷的排泄通过粪便和尿液减少,表明砷在体内的积累更高。形态研究表明,尿液中的砷主要是有机砷,而毛发中则积累了等量的亚砷酸盐、砷酸盐和有机砷。山羊通过粪便排泄大量的有机砷,可能是由于有机砷通过肝胆分泌进入肠道。血清丙氨酸氨基转移酶和天冬氨酸氨基转移酶活性显著升高(p<0.05),以及肝脏的组织病理学变化表明存在肝毒性。随着时间的推移,尿液中亚砷酸盐的比例增加,有机比例减少,这表明砷在山羊肝脏中被甲基化。因此,该研究暗示,如果动物长期暴露,毒性会加重,因为肝毒性会导致甲基化减少,有机砷的形成减少,通过尿液排泄减少。