β2肾上腺素受体介导酪氨酸促泰和乌骨鸡十二指肠黑色素生成研究

发布时间：2018-03-22 16:17

本文选题：泰和乌骨鸡　切入点：酪氨酸　出处：《江西农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：本实验通过以泰和乌骨鸡为模型,在基础日粮中添加酪氨酸,酪氨酸浓度分别为0.38%、0.58%、0.78%、0.98%、1.18%、1.38%、1.58%和1.78%这8个处理组和1个对照组。通过研究比较第15天、第29天、第43天和第57天的相同饲养条件下在饲料中添加不同浓度酪氨酸,检测十二指肠β2肾上腺素受体(β2-AR)、酪氨酸酶(TYR)表达水平,阐明β2-AR介导泰和乌骨鸡黑色素的生成机理。常规光镜技术显示,泰和乌骨鸡十二指肠分为黏膜、黏膜下层、肌层和浆膜,黑色素主要分布于肌层。这说明黑色素不仅存在于皮肤中,也存在于其它内脏器官、组织中。DOPA染色显示黑色素细胞存在于泰和乌骨鸡的固有层和隐窝上。免疫组化和免疫荧光的方法检测泰和乌骨鸡十二指肠中TYR阳性细胞和β2-AR阳性细胞的分布规律,发现β2-AR阳性细胞和TYR阳性细胞主要分布于十二指肠的隐窝、固有层、黏膜下层和肠绒毛,且两者在同一部位均有表达。饲喂酪氨酸可以增加β2-AR阳性细胞和TYR阳性细胞的数量。嗜银染色显示,嗜银细胞分布于固有层和隐窝上,与β2-AR的分布位置一致,嗜银细胞表面存在β2-AR,而嗜银细胞可以分泌多种物质介导黑色素的合成,因此提示β2-AR可以通过对嗜银细胞的影响,从而促进黑色素的合成。饲喂酪氨酸可以增加嗜银细胞的数量。WB技术测定泰和乌骨鸡十二指肠β2-AR和TYR蛋白表达水平。结果表明,随着酪氨酸浓度的升高,β2-AR和TYR蛋白合成量也升高,1.18%酪氨酸组β2-AR和TYR基因和蛋白表达水平最高。然而酪氨酸浓度超过1.18%后,两个指标增速减慢甚至呈下降趋势。综上所述,0.38%-1.18%酪氨酸能促进鸡十二指肠内TYR和β2-AR蛋白表达上调,诱导黑色素合成分泌,促进黑色素在十二指肠内积累。β2-AR蛋白表达量与酪氨酸浓度相关,提示β2-AR信号通路可介导泰和乌骨鸡黑色素的生成。
[Abstract]:In this experiment, using Taihe silky chicken as a model, adding tyrosine to the basal diet, the concentration of tyrosine was 0.38, 0.58 and 0.98, respectively. The eight treatment groups, 1.38%, 1.38% and 1.78%, and a control group, were compared on the 15th day, the 29th day, the control group, the control group, the control group and the control group. Under the same feeding conditions on day 43 and day 57, different concentrations of tyrosine were added to feed to detect the expression of 尾 _ 2-adrenergic receptor (尾 _ 2-ARR) in duodenum. To elucidate the mechanism of 尾 2-AR mediated melanin formation in Taihe silky chickens. The routine light microscopy showed that the duodenum of Taihe silky chickens was divided into mucous membrane, submucosal layer, muscular layer and serous membrane. Melanin is mainly distributed in the myometrium. This indicates that melanin exists not only in the skin, but also in other visceral organs. The staining of .DOPA showed that melanocytes existed in the lamina propria and crypt of Taihe silky chicks. The distribution of TYR positive cells and 尾 2-AR positive cells in the duodenum of Taihe silky chickens was detected by immunohistochemistry and immunofluorescence. It was found that 尾 2-AR positive cells and TYR positive cells were mainly distributed in duodenal crypt, lamina propria, submucosa and villi. Tyrosine could increase the number of 尾 2-AR positive cells and TYR positive cells. The results of argyrophilic staining showed that the silver cells distributed in the lamina propria and crypt, which was consistent with the distribution of 尾 2-AR. There is 尾 _ 2-ARon on the surface of argyrophilic cells, which can secrete a variety of substances to mediate melanin biosynthesis. It is suggested that 尾 2-AR can be mediated by the effect of 尾 _ (2-ARR) on argyrophilic cells. Tyrosine could increase the number of argyrophilic cells. WB technique was used to detect the expression of 尾 2-AR and TYR protein in duodenum of Taihe silky chicken. With the increase of tyrosine concentration, the synthesis of 尾 2-AR and TYR protein also increased in 1.18% tyrosine group. However, when tyrosine concentration exceeded 1.18%, the expression level of 尾 2-AR and TYR gene and protein was the highest. In conclusion, 0.38-1.18% tyrosine could promote the up-regulation of TYR and 尾 2-AR protein expression and induce melanin synthesis and secretion in the duodenum of chicken. 尾 2-AR protein expression was correlated with tyrosine concentration, suggesting that 尾 2-AR signaling pathway could mediate the formation of melanin in Taihe silky chickens.
【学位授予单位】：江西农业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S831

【参考文献】