动物营养学报2016，Vol.28Issue(5)：1615-1625,11.DOI:10.3969/j.issn.1006-267x.2016.05.040
热应激通过诱导奶牛乳腺细胞凋亡减少乳蛋白
Heat-Stress Decreases Milk Protein through Induction of Mammary Cells Apoptosis of Cows
摘要
Abstract
This experiment was conducted to investigate the relationship among the decrease of milk protein content and yield under heat stress, hormones related to lactation, pathways involved in milk protein synthesis, and apoptosis of mammary cells, and to find reasons for milk protein decline caused by heat stress. Four health⁃y multiparous lactating Holstein cows with similar days in milk, body weight and milk yield were used as ex⁃periment animals. Crossover design was applied, there were two experimental periods, and each period lasted for 18 days ( 9 d of pretrial period, and 9 d of trail period) with 30 d between the two periods. Cows in pretrial period were exposed to thermal neutral conditions and allowed to eat ad libitum. Cows in trial period were ran⁃domly divided into two groups ( n=2) , which were heat stress group and pair⁃restricted feeding group. The re⁃sults showed as follows: 1) heat stress significantly decreased milk protein yield and content (P<0.05). 2) Heat stress had no significant influence on Janus kinase ( JAK)⁃signal transducer and activator of transcription ( STAT) pathway andκ⁃casein ( CSN3) gene expression ( P>0.05) . 3) In mTOR pathway, heat stress signifi⁃cantly increased the expression of mammalian target of rapamycin ( mTOR) gene ( P<0.05) , and had the tend⁃ency to increase the expression of ribosomal protein S6 kinase (S6K1) gene (0.05≤P<0.10). 4) Heat stress significantly increased the expressions of Caspase⁃3 ( CASP3) and cyclooxygenase⁃2 ( COX2) genes involved in apoptosis (P<0.05), and had the tendency to increase the expression of B⁃cell lymphoma⁃2⁃associated X protein (BAX) (0.05≤P<0.10). It is concluded that heat stress may not be able to decline milk protein con⁃tent and yield through regulating the capacity of individual mammary cells, but thorough induction of apoptosis of the mammary cells and decrease of the quantity of mammary cells used for milk protein synthesis.关键词
热应激/乳蛋白/JAK-STAT/mTOR/细胞凋亡Key words
heat stress/milk protein/JAK-STAT/mTOR/apoptosis分类
农业科技引用本文复制引用
高胜涛,郭江,权素玉,南雪梅,卜登攀..热应激通过诱导奶牛乳腺细胞凋亡减少乳蛋白[J].动物营养学报,2016,28(5):1615-1625,11.基金项目
国家自然科学基金（31372341）；十二五国家科技支撑计划（2012BAD12B02-05）；中国农业科学院科技创新工程 （）
