热胁迫下奶牛肝脾HSP70的表达特征及脾淋巴细胞凋亡

为了探讨热胁迫对奶牛组织形态和机能的影响,对热胁迫奶公犊肝、脾进行了显微结构观察,分析了HSP70在肝、脾的表达特征,并进行了脾淋巴细胞凋亡的观察。结果表明:在25℃常温状态下,奶牛肝、脾结构基本一致;脾组织内淋巴小结界限较大,红髓、白髓结构完整性较好,边缘被膜平整,淋巴小结内的淋巴细胞排列较致密。在不同热胁迫下,各组奶牛肝、脾均有不同程度的损伤,而且肝、脾细胞的超微结构变化随热胁迫后不同时间点而有所不同。热应激奶牛组织中HSP70含量随胁迫时间的延长呈现波动变化,与同期各组织细胞所呈现的病理损伤变化存在一定的相关,提示HSP70含量可作为判定组织应激损伤的标志之一。热胁迫对奶牛器官组织的影响是逐渐加重的过程,呈现部分淋巴细胞从凋亡到坏死的病理学变化过程。不同高温热胁迫均可造成肝、脾结构及其细胞的损伤,温度越高损伤越重。

Expression profiles of HSP70 in liver and spleen of cows as well as spleen lymphocyte apoptosis under heat stress

To investigate the effects of heat stress on histomorphology and function of cows,the histology of liver and spleen of initial stage of weaning calf under experimental heat stress was observed,the expression profiles of HSP70 in liver and spleen were analyzed,and the spleen lymphocyte apoptosis was also assayed.The result showed that the structure of liver and spleen in each group revealed no difference at normal temperature condition.Compared with 25℃ condition,cows had the larger bounds of microfold,the better structural and functional of red-eared slide and white-eared slide,the more compact lymphocyte arrangement of microfold in spleen,which reflected the difference in tissue structure and caused the difference in heat resistance.The different heat stress could damage liver and spleen at different degrees in all groups,and the ultrastructure changed with the heat stress times. The contents of HSP70 showed a curve change with the heat stress times and had a certainty relation with histiocyte damages,which inferred that the contents of HSP70 could be as one of indicators to determinate histiocyte damages.The damages degree of organs and tissues in cows with heat stress was gradually aggravated,part of lymphocyte were showed from apoptosis to putrescence as the hyperthermia stress increase,the damages of structures and cells in liver and spleen aggravated.