地塞米松对山羊皮质醇分泌和瘤胃生物钟基因表达的影响  

Effects of dexamethasone on cortisol secretion and ruminal epithelium clock gene expressions in goats

作　　者：罗燕文 耿雅丽[1] 华灿枫 陈渠[1] 牛丽琼[1] 倪迎冬[1] 

机构地区：[1]南京农业大学农业部动物生理生化重点开放实验室,江苏南京210095

出　　处：《畜牧与兽医》2017年第6期100-105,共6页Animal Husbandry & Veterinary Medicine

基　　金：国家重大基础研究发展计划973项目(2011CB100802)

摘　　要：为了研究地塞米松对山羊皮质醇分泌和瘤胃生物钟基因表达的影响,试验选用10只装有永久性瘤胃瘘管的波尔杂交山羊,随机分为对照组(n=5)和地塞米松组(n=5),对照组注射生理盐水,地塞米松组注射地塞米松(0.2 mg/kg),每天注射1次,连续注射21 d。试验结束后,采集血液和瘤胃组织;放射免疫分析法(radioimmunoassay,RIA)检测血浆皮质醇含量;Real-time PCR检测瘤胃生物钟基因表达量。结果显示:与对照组相比,地塞米松组血浆皮质醇浓度显著降低(P<0.05),瘤胃液中皮质醇浓度无显著变化(P>0.05),瘤胃上皮组织中永恒蛋白基因(Tim)和肌肉芳香烃受体核转运样蛋白1(Bmal1)mRNA表达显著上调(P<0.05);相关性分析结果显示:血浆皮质醇浓度与瘤胃上皮组织中Tim(R=-0.64,P=0.08)和Bmal1(R=-0.62,P=0.09)mRNA表达呈负相关趋势,瘤胃中皮质醇浓度与瘤胃上皮组织中Bmal1 mRNA表达呈显著负相关(R=-0.84,P<0.05)。结果提示,外源性地塞米松降低山羊体内内源性皮质醇的生成,上调瘤胃上皮组织中生物钟基因的表达,且生物钟基因表达水平与血液、瘤胃液中皮质醇浓度呈高度负相关。The present experiment was conducted to assess the effect of dexamethasone on cortisol secretion and ruminal epithelium circadian clock gene expressions in goats. Ten rumen-cannulated boer goats were randomly allocated to the control（ Con,n = 5） and dexamethasone groups（ Dex,n = 5）. Control goats were injected with saline（ 0. 2 mg/kg） and Dex group injected with dexamethasone（ 0. 2 mg/kg）once a day for 21 days. Blood and ruminal epithelial tissue were collected after goats were slaughtered. Plasma concentrations of cortisol were detected by radioimmunoassay and expressions of clock genes in ruminal epithelium detected by real-time PCR. The results showed that plasma cortisol levels were significantly decreased in Dex group（ P 〈 0. 05）,while,gene expressions of clock genes of Tim（ P 〈 0. 05） and Bmal1（ P〈0. 01） in ruminal epithelium significantly up-regulated. The correlation analysis showed that a tendency of negative correlation between plasma cortisol and mRNA expression of Tim（ R =-0. 64,P = 0. 08） and Bmal1（ R =-0. 62,P = 0. 09） genes in ruminal epithelium,and a strong negative correlation between ruminal cortisol and Bmal1 mRNA expression（ R =-0. 84,P〈 0. 05） were found. These results suggested that exogenous dexamethasone treatment decreases endogenous cortisol secretion and up-regulates clock genes expression in ruminal epithelium. In addition,there is a significant correlation between the level of cortisol and clock genes expression in the rumen epithelium.

关 键 词：地塞米松 皮质醇 生物钟基因 瘤胃 山羊 

分 类 号：S827[农业科学—畜牧学]