应激对家禽大麻素受体信号的影响研究

发布时间：2019-06-14 12:16

【摘要】：为探讨CB1受体信号通路在应激调控食欲过程中起到的作用,本课题进行了以下研究。本研究通过测定不同日龄家禽各组织中CB1受体的表达量,研究CB1受体的时空分布。选择体重相近的7,21和35日龄的肉仔鸡和7日龄蛋公雏各8只,采集下丘脑,肝脏,十二指肠,空肠,回肠。试验结果显示,在7,21和35日龄的肉仔鸡和7日龄蛋公雏中,CB1受体在下丘脑中的表达量均远高于其他外周组织,且下丘脑中CB1受体的表达量随日龄的增加而显著增加,在7日龄时,肉仔鸡和蛋公雏各组织中CB1受体的表达量并不存在差异。本研究通过热应激和糖皮质激素DEX处理,研究应激时CB1受体及相关基因表达的变化情况。热应激试验:选择体重相近的28日龄雄性AA肉仔鸡144只,分为四组(10h热应激组,10h对照组,72h热应激组,72h对照组),每组6个重复,每个重复6只鸡。DEX试验:选择体重相近的28日龄雄性AA肉仔鸡144只,分为四组(24h DEX组、24h对照组,72h DEX组,72h对照组),每组6个重复,每个重复6只鸡。试验结果显示,应激(热应激和DEX处理)可导致采食量和体增重的显著降低,肛温的显著升高。热应激时,肉仔鸡下丘脑中GR mRNA表达量显著增加,AMPK?1mRNA表达量显著降低,AMPK磷酸化水平降低。DEX处理时,肉仔鸡下丘脑中GR、AMPK??、LKB1、CB1受体mRNA的表达量显著升高,AMPK磷酸化水平升高。说明,糖皮质激素可以激活CB1受体和AMPK信号通路,从而调控了食欲,能量代谢和平衡。本研究通过脑室注射CB1受体激活剂ACEA和拮抗剂SR141716,研究CB1受体对AMPK信号通路的影响。两个试验均选择体重165g左右的7日龄肉仔鸡40只进行脑室埋管,恢复至10日龄进行脑室注射,脑室注射SR141716分为DMSO组,0.1,1,2ugSR141716组,脑室注射ACEA分为DMSO组,0.5,1,2ug ACEA组,每半小时统计采食量。根据结果分别选择1ug SR141716和2ug ACEA为最佳注射剂量,1h和3h为最佳采样时间,进行重复试验。试验结果显示,脑室注射SR141716使肉仔鸡采食量下降,下丘脑中CB1受体、AMPK?2、CART mRNA表达量显著升高,AgRP、POMC mRNA表达量显著降低。说明,抑制CB1受体可通过降低促食欲基因AgRP的表达,升高抑食欲基因CART的表达,抑制家禽食欲。脑室注射ACEA可增加肉仔鸡的采食量,降低了其下丘脑中CB1受体、POMC mRNA的表达水平,升高了AgRP的mRNA表达水平。说明,激活CB1受体可通过增加促食欲基因AgRP的表达,促进家禽食欲。本研究表明,家禽CB1受体在下丘脑中高度表达,并广泛分布在肝脏、肠道等外周组织。糖皮质激素可通过激活CB1受体信号通路和AMPK信号通路,调控家禽食欲。CB1受体可通过调控AMPK及其下游的食欲调控因子,调控家禽食欲。
[Abstract]:In order to investigate the role of CB1 receptor signaling pathway in the regulation of appetite by stress, the following studies were carried out. In this study, the temporal and spatial distribution of CB1 receptor was studied by measuring the expression of CB1 receptor in poultry tissues of different ages. Eight broilers of 7, 21 and 35 days old and 8 7-day-old male chicks of 7, 21 and 35 days old were selected to collect hypothalamus, liver, duodenum, Jejunum and ileum. The results showed that the expression of CB1 receptor in Hypothalamus was much higher than that in other peripheral tissues in 7, 35-day-old broilers and 7-day-old egg chicks, and the expression of CB1 receptor in hypothalamus increased significantly with the increase of age. At 7-day-old broilers and egg-male chicks, there was no difference in the expression of CB1 receptors between broilers and egg chicks. In this study, the changes of CB1 receptor and related gene expression during stress were studied by heat stress and glucocorticoid DEX treatment. Heat stress test: 144 28-day-old male AA broilers with similar body weight were divided into four groups (10 h heat stress group, 10 h control group, 72 h heat stress group, 72 h control group), 6 repeats in each group, 6 chickens in each group. Dex test: 144 28-day-old male AA broilers with similar body weight were divided into four groups (24 h DEX group, 24 h control group, 72 h DEX group, 72 h control group), 6 chickens in each group. The results showed that stress (heat stress and DEX treatment) could significantly decrease feed intake and body weight gain, and increase anal temperature. During heat stress, the expression of GR mRNA was significantly increased, the expression of AMPK?1mRNA was significantly decreased, and the phosphorylation level of AMPK was decreased. The expression of GR,AMPK??,LKB1,CB1 receptor mRNA and AMPK phosphorylation were significantly increased and AMPK phosphorylation was increased in the hypothalamus of broilers treated with DEX. It is suggested that glucocorticoids can activate CB1 receptor and AMPK signaling pathway, thus regulating appetite, energy metabolism and balance. In this study, the effect of CB1 receptor on AMPK signaling pathway was studied by intracerebroventricular injection of CB1 receptor activating agent ACEA and antagonist SR141716,. In both experiments, 40 7-day-old broilers weighing about 165 g were selected for intraventricular catheterization and restored to 10 days of age for intraventricular injection. SR141716 was divided into DMSO group, 0.1, 1, 2ugSR141716 groups. Intraventricular injection of ACEA was divided into DMSO group, 0.5 g group and 2ug ACEA group, and the feed intake was counted every half hour. According to the results, 1ug SR141716 and 2ug ACEA were selected as the best injection dose, 1 h and 3 h as the best sampling time, respectively, and the repeated tests were carried out. The results showed that intraventricular injection of SR141716 decreased feed intake, increased the expression of CB1 receptor and AMPK?2,CART mRNA and decreased the expression of AgRP,POMC mRNA in hypothalamus. It is suggested that inhibition of CB1 receptor can inhibit appetite of poultry by decreasing the expression of appetite promoting gene AgRP and increasing the expression of appetite gene CART. Intraventricular injection of ACEA increased feed intake, decreased the expression of CB1 receptor, POMC mRNA and increased the expression of mRNA in AgRP. It is suggested that the activation of CB1 receptor can promote the appetite of poultry by increasing the expression of appetite promoting gene AgRP. This study showed that CB1 receptor was highly expressed in the Hypothalamus and widely distributed in the liver, intestine and other peripheral tissues. Glucocorticoids can regulate poultry appetite by activating CB1 receptor signaling pathway and AMPK signaling pathway. CB1 receptor can regulate poultry appetite by regulating AMPK and its downstream appetite regulators.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S831

【共引文献】