摘要
目的：通过锌对热应激大鼠垂体阿黑皮素原（ＰＯＭＣ）ｍＲＮＡ表达的影响研究，探讨锌对热应激大鼠的保护机理。方法：２０只ＳＤ雄性大鼠随机等分４组，即高锌高温暴露组（Ａ组）、中锌高温暴露组（Ｂ组）、低锌高温暴露组（Ｃ组）和正常锌室温对照组（Ｄ组）。在ＡＩＮ－９３Ｍ饲料配方基础上，以碳酸锌为锌源，配制成高锌、中锌、低锌和正常锌饲料，每公斤饲料锌含量测定值分别为９２．２ｍｇ、４５．６１ｍｇ、２１．７０ｍｇ和４５．６１ｍｇ。４组大鼠在室温下饲以相应饲料１４天后，将Ａ、Ｂ、Ｃ组大鼠置于高温室（Ｔｄｂ４０℃，Ｔｗｂ３０．８℃）中连续暴露３小时。用Ｎｏｒｔｈｅｒｎｂｌｏｔ杂交分析法（探针为地高锌标记的ＰＯＭＣｃＲＮＡ），观察垂体ＰＯＭＣｍＲＮＡ表达水平。结果：（１）高温应激可使大鼠垂体ＰＯＭＣｍＲＮＡ表达水平增高；（２）高锌摄入可使热应激大鼠垂体ＰＯＭ－ＣｍＲＮＡ表达水平升高，而低锌摄入则相反。结论：锌对热应激大鼠垂体ＰＯＭＣ基因有调控作用。
Objective: In order to probe the protective mechanism of zinc in heat stressed rats, the effect of zinc on pituitary POMC mRNA expression was studied in heat exposed rats. Methods: 20 Sprague Dawley male rats were randomly divided into 4 groups, i. e., high zinc hyperthermal exposure group (Group A), middle zinc hyperthermal exposure group (Group B), low zinc hyperthermal exposure group (Group C) and normal zinc room temperature control group (group D). On the basis of AIN 93M diet composition, high, middle, low and normal zinc diets were prepared by adding or reducing zinc carbonate. Zinc contents of high、 middle、 low and normal zinc diets per kilogram were 92.20, 45.61 、21.70 and 45.61mg respectively. Rats were fed for 14 days in room temperature. Then rats in group A、B and C were placed in high temperature room (Tdb 40℃, Twb 30.8℃) to be exposed continuously for 3 hours. Pituitary POMC mRNA expression was analyzed by Northern blot analysis (using Dig labeled POMC cRNA probe). Results: 1. Hyperthermal stress could enhance POMC mRNA expression in rat pituitary. 2. High zinc intake could raise pituitary POMC mRNA expression level in heat stressed rats whereas low zinc diet intake could lower pituitary POMC mRNA expression. Conclusion: Diet zinc can modulate pituitary POMC mRNA expression level in heat stressed rats.
出处
《营养学报》
CAS
CSCD
北大核心
1998年第3期294-298,共5页
Acta Nutrimenta Sinica
基金
博士研究生经费
