碘硒缺乏对黄牛自由基及甲状腺激素代谢的研究

为了阐明低碘低硒环境中黄牛血液自由基及甲状腺激素代谢的变化规律和发生机理，本文选取黑龙江省五常市牛家镇自然状态下生长的１５头黄牛，随机分为３组，每组５头，其中（１）组每日补碘（碘化钾）０．７ｍｇ·ｋｇ－１；（２）组每日补硒（亚硒酸钠）０．２ｍｇ·ｋｇ－１，（３）组每日补碘硒分别为０．７ｍｇ·ｋｇ－１和０．２ｍｇ·ｋｇ－１。连续饲喂一个月。于试验的第０ｄ和３０ｄ，分别对血液谷胱甘肽过氧化物酶（ＧＳＨ—ｐｘ）、过氧化氢酶（ＣＡＴ）、血液自由基（ＦＲ）水平和红细胞超氧化物歧化酶（ＳＯＤ）、丙二醛（ＭＤＡ）以及血清Ｔ３、Ｔ４、ＴＳＨ含量进行系统检测。结果显示，当地黄牛饮水碘３．８２μｇ·Ｌ－１，饲料碘０．２８５ｍｇ·ｋｇ－１，饲料硒０．０４９８ｍｇ·ｋｇ－１，血清蛋白结合碘７．０２μｇ·（１００ｍＬ）－１，全血硒０．１４ｍｇ·Ｌ－１，周围生活的人群甲状腺肿占２１．８０％。综合分析，试验区为低碘低硒环境。结果表明；３组黄牛全血ＧＳＨ－ｐｘ、ＣＡＴ活性极显著地升高，自由基净含量明显下降，血清Ｔ３、含量升高，ＴＳＨ降低、加碘组Ｔ４含量升高，加硒组Ｔ４略有升高，但统计不明显，碘硒组Ｔ４含量有所下降。红细胞ＳＯＤ和ＭＤＡ在整?

STUDIES ON THE FREE RADICALS AND THYROID HORMONE METABOLISM IN BOVINE WITH IODINE AND SELENIUM DEFICIENCY

In order to interpret the pathologic mechanism of free radicals metabolism and thyroid hormone metabolism in bovine which was in iodine and selenium deficient condition, 15 bovines selected from Niujia town, Wuchang city, Heilongjiang province, China ,and were devided into 3 groups randomly with 5 cattles in each group,The three groups cattles were supplemented with 07mgkg iodine(first group), 02mgkg selenium(soecond group) and 07mgkg iodine plus 02mgkg selenium(third group) per day of 30 days, respectively. The whole blood glutathione peroxidase (GSH-px) and catalase (CAT) activities, free radicals (FR) concentration ,erythrocyte superoxidase dismutase (SOD) activity and molonaldehyde (MDA) concentration ,the serum triiodothyronine (T3)thyroxine (T4) and thyrotropin (TSH) were measured on the day of supplement day-0 and day-30, respectively. 1t was showed that the average iodine in drinking water and diet contained 382gL and 0285mgkg,the diet selenium was 00498mgkg,serum protein bound iodine (PBI lodine Selenium Bovine) was 702g100ml,blood selenium was 014mgL,the schoolchildrens goiter werr 218%. the results indicated that the iodine and the selenium were deficient in the investigaed area. The whole blood GSHpx and CAT activities were significantly higher (p<001) in the three groups, The T4 in the first group was higher (p<005) ,Although the T4 in the second group was also higher. but lt was not significant, the T4 was lower in the chird group. The SOD and MDA in erythrocyte did not differ in the experimental periods,the results also showed that the increased range of GSHpx and CAT activities, and decreased degree of FR in the third group were better than the other two groups, the thyroid hormone metabolism was more coincided with the physiologic status in the third group. the iodine and the selenium played an important role in the pathologic process of free radical metabolic disorder. selenium not only displayed the function of antioxidantion through effect the activities of GSH-px and CAT activities, but alos effect through derectly scavenging on free radicals. The iodine made the serum T3T4 higher and TSH lower, iodine deficiency results in the Goiter ,the Selenium deficiency aggravate the iodine deficiency effect, the iodine and the selenium were dependent and conditioned each other in the course of free radicals and thyroid hormone metabolism, they had synergistic effect.