Swarup D, Naresh Ram, Varshney V P, Balagangatharathilagar M, Kumar P, Nandi D, Patra R C
Environmental Medicine Laboratory, Division of Medicine, Indian Veterinary Research Institute, Izatnagar 243122, UP, India.
Res Vet Sci. 2007 Feb;82(1):16-21. doi: 10.1016/j.rvsc.2006.05.002. Epub 2006 Jul 5.
The present study was carried out to assess the endocrine status and liver function in adult cows reared in polluted environment around different industrial units in India. The effect on endocrine system was examined by determination of plasma level of thyroid hormones, thyroxin (T4) (n=269) and triidothyronin (T3) (n=269), stress hormone cortisol (n=266), and reproductive hormones such as estradiol (n=84) and progesterone (n=84) in cows (>3 years) reared around different polluted industrial and non-polluted areas. The respective blood lead and cadmium concentration was also determined in all the cows. The mean plasma levels of both T3 and T4 were significantly (P<0.05) higher around lead zinc smelter (2.43+/-0.26 and 41.1+/-2.9nmol/L) and closed lead cum operational zinc smelter (1.81+/-0.16 and 42.4+/-6.2nmol/L), where the mean blood lead level (0.86+/-0.06 and 0.51+/-0.09mug/ml) was also significantly higher than that of cows (0.07+/-0.01mug/ml) from unpolluted areas. Regression analysis of data from 269 cows revealed a significant (P<0.01) positive correlation between the blood lead and plasma T3 (r=0.287) and T4 (r=0.173). The correlation between thyroidal hormones and the blood cadmium concentration (r=-0.079 and -0.48; P>0.05) was not significant. Plasma cortisol level had also a non-significant (P>0.05) correlation (r=-0.092) with blood lead level.However, the mean cortisol level (4.02+/-1.96nmol/L) of cows in phosphate rock mining areas was significantly (P<0.05) higher than that of controls (1.98+/-0.70nmol/L). The mean plasma estradiol level was significantly (P<0.05) higher in cows around closed lead cum operational zinc smelter (47.1+/-19.5pg/ml) than that of the control animals (21.8+/-3.9pg/ml) and in rest of the areas, the difference did not reach the statistical significance (P>0.05). The serum biochemical analysis in 36 cows around lead-zinc smelter with the highest mean blood lead level (0.86+/-0.06mug/ml) amongst all the industrial/urban areas surveyed, and in 15 animals from non-polluted areas revealed a significant positive correlation between blood lead and serum ALT (alanine transaminase) (r=0.688, P<0.01) and AST (aspartate transaminase) (r=0.390, P<0.01) and a negative correlation with serum total lipids (r=-0.337, P<0.05), total protein (r=-0.449, P<0.01) and albumin(r=-0.662, P<0.01). It is concluded from the study that the natural exposure to lead in polluted environments disturbs the endocrine profile and the higher blood lead level alters serum biochemical parameters indicative of liver functions.
本研究旨在评估印度不同工业单位周边污染环境中成年母牛的内分泌状况和肝功能。通过测定来自不同污染工业区和非污染区的3岁以上母牛血浆中的甲状腺激素水平（甲状腺素（T4）（n = 269）和三碘甲状腺原氨酸（T3）（n = 269））、应激激素皮质醇（n = 266）以及生殖激素如雌二醇（n = 84）和孕酮（n = 84），来检测对内分泌系统的影响。同时也测定了所有母牛血液中的铅和镉浓度。在铅锌冶炼厂附近（2.43±0.26和41.1±2.9nmol/L）以及关闭的铅联合运营锌冶炼厂附近（1.81±0.16和42.4±6.2nmol/L），T3和T4的平均血浆水平均显著升高（P<0.05），且这两个地方的平均血铅水平（0.86±0.06和0.51±0.09μg/ml）也显著高于来自无污染地区的母牛（0.07±0.01μg/ml）。对269头母牛的数据进行回归分析发现血铅与血浆T3（r = 0.287）和T4（r = 0.173）之间存在显著的正相关（P<0.01）。甲状腺激素与血镉浓度之间的相关性（r = -0.079和-0.48；P> >0.05）不显著。血浆皮质醇水平与血铅水平之间也存在不显著的相关性（r = -0.092，P> >0.05）。然而，磷矿开采区母牛的平均皮质醇水平（4.02±1.96nmol/L）显著高于对照组（1.98±0.70nmol/L）（P<0.05）。关闭的铅联合运营锌冶炼厂附近母牛的平均血浆雌二醇水平（47.1±19.5pg/ml）显著高于对照动物（21.8±3.9pg/ml）（P<0.05），在其他区域差异未达到统计学显著水平（P> >0.05）。在所有调查的工业/城市区域中，血铅平均水平最高（0.86±0.06μg/ml）的铅锌冶炼厂附近的36头母牛以及15头来自无污染地区的动物的血清生化分析显示，血铅与血清谷丙转氨酶（ALT）（r = 0.688，P<0.01）和谷草转氨酶（AST）（r = 0.390，P<0.01）呈显著正相关，与血清总脂质（r = -0.337，P<0.05）、总蛋白（r = -0.449，P<0.01）和白蛋白（r = -0.662，P<0.01）呈负相关。研究得出结论，在污染环境中自然接触铅会扰乱内分泌状况，且较高的血铅水平会改变指示肝功能的血清生化参数。
