摘 要：
研究泌乳素、氢化可的松和胰岛素3种泌乳激素及其组合以及苏氨酸和苯丙氨酸比例对体外培养的奶牛乳腺组织中乳蛋白合成的影响。结果表明,催乳素、氢化可的松和胰岛素的质量浓度分别为500、1 000和5 000、10 000和50 000μg/L时,显著增加α_(s1)酪蛋白的mRNA丰度。质量浓度为500μg/L的催乳素和5 000μg/L的胰岛素则显著提高乳蛋白的合成。而当3种泌乳激素质量浓度分别为催乳素500μg/L、氢化可的松1 000μg/L和胰岛素5 000μg/L时,最能促进乳腺组织中α_(s1)酪蛋白基因表达和乳蛋白合成;当Thr/Phe为1.05∶1时,α_(s1)酪蛋白mRNA丰度达到最高。Thr/Phe比例为1.02∶1时,最利于乳蛋白的合成。说明:培养液中催乳素、氢化可的松和胰岛素的质量浓度分别为500、1 000和5 000μg/L,Thr/Phe比例为1∶1时最利于体外培养的奶牛乳腺组织中乳蛋白合成。
译 名：
Effects of Lactogenic Hormones and Ratio of Threonine to Phenylalanine on Milk Protein Synthesis in Cultured Bovine Mammary Gland
作 者：
ZHOU Miaomiao;CUI Jingxiang;Institute of Animal Science,Weifang University of Science and Technology;
关键词：
Lactogenic hormones;;Threonine;;Phenylalanine;;Milk protein
摘 要：
This study was to investigate effects of lactogenic hormones(prolactin,hydrocortisone or insulin)and ratio of threonine(Thr)to phenylalanine(Phe)onα_(s1)casein gene expression and milk protein synthesis in cultured bovine mammary gland.Mammary tissues was obtained from Holstein dairy cow and incubated in DMEM/F12.Concentrations of prolactin,hydrocortisone or insulin or Thr,Phe in the experimental medium were adjusted.After incubated with experimental medium,tissues were collected for gene expression examination and medium was collected for milk protein determination.The results showed thatα_(s1) casein gene expression was enhanced by the addition of 500μg/L prolactin,1 000 and 10 000μg/L hydrocortisone,5 000 and 50 000μg/L insulin.Milk protein synthesis was improved by the addition of 500μg/L prolactin,and 5 000μg/L insulin.Theα_(s1)casein gene expression and milk protein synthesis was the highest when 500μg/L prolactin,1 000μg/L hydrocortisone and 5 000μg/L insulin were added at the same time.Ratio of Thr to Phe at 1∶1significantly increasedα_(s1)casein gene expression and milk protein synthesis.These results indicate that concentration of lactogenic hormones and ratio of Thr to Phe were important for milk protein synthesis.
