急性冷暴大鼠ACTH分泌及锌代谢的变化

Changes of ACTH secretion and zinc metabolism in rats during acute cold exposure *

目的：观察急性冷暴过程中大鼠ＡＣＴＨ分泌及锌代谢的变化情况．方法：雄性ＳＤ大鼠３２只，随机分为４组，１组为室温对照组（２０℃±１℃），２，３组分别于－１５℃冷暴１５ｍｉｎ和６０ｍｉｎ，４组－１５℃冷暴６０ｍｉｎ后室温１５ｍｉｎ．动物处理后立即宰杀，测定血浆ＡＣＴＨ，血清、肝脏和骨骼肌锌含量．结果：大鼠冷暴１５ｍｉｎ时，血浆ＡＣＴＨ即明显升高，冷暴６０ｍｉｎ及恢复１５ｍｉｎ后仍处于较高水平（Ｐ＜０．０５）．大鼠冷暴１５ｍｉｎ时血清锌开始降低，在冷暴６０ｍｉｎ时降低明显（Ｐ＜０．０５），室温恢复１５ｍｉｎ后，仍处于较低水平（Ｐ＜０．０５）．大鼠冷暴后，肝脏锌含量升高明显（Ｐ＜０．０５），骨骼肌锌有升高趋势．结论：急性冷暴过程中大鼠ＡＣＴＨ分泌持续升高。

Aim:To study the changes of ACTH secretion and zinc metabolism in rats during acute cold exposure. Methods: Thirty two male SD rats were randomized into 4 groups. Group 1 served as the control group, and rats of groups 2 and 3 were treated in the temperature of -15℃ for 15 min and 60 min, and rats of group 4 were treated at the temperature of -15℃ for 60 min and at room temperature for 15 min, respectively. Immediately after treatment, rats were sacrificed for the detection of plasma ACTH, the level of zinc in the serum and tissues. Results: The ACTH concentration in the plasma of group 2 increased significantly than that of the control ( P <0.05), it still remained at the high level in groups 3 and 4. The concentrations of zinc in serum of groups 2, 3, and 4 were reduced more significantly than those of the control ( P <0.05). There was a significant increase in the content of zinc in the liver after cold exposure. Conclusion: The findings indicate that acute cold exposure can lead to an increase in ACTH secretion and zinc redistribution in body.