摘要
目的 研究TxB2、PGFIa、PRL、CORT、TSA等生化指标及小肠上皮细胞膜结构在热应激中变化的规律。方法 应用生化、酶学、放免法检测相关的生化指标。采用冷冻蚀刻技术,定量分析大鼠小肠上皮细胞膜内微粒的数量及分布状况。结果 热应激动物体温迅速上升;受检生化指标明显异常;小肠上皮细胞膜,核膜EF面及PF面的膜内微粒数量均有明显减少和异常分布,且累及范围较为广泛,负荷能加重其异常改变的程度;热暴露停止4—24h上述各项指标无明显恢复迹象。结论(1)热应激能迅速破坏小肠上皮细胞的膜性结构,其程度与受热时间长短,体温高低呈反比。(2)可导致对机体有害的TxB2大量释放,对机体有保护作用的PGFIa水平降低,以及与继发损伤有关的CORT持续上升和TSA的异常增高,最终导致全身系统,多器官,多种细胞成分的广泛受损;(3)受热停止4～24h,上述各项指标均无明显恢复迹象,迟发性损伤明显。
Objective To study the changing regulation of the biochemical indexes and the membranous structure of the intestinal epithelium in heat stress. Methods The TxB2 PGFla,PRL,CORT and TSA were measured with the techniques of biochemistry and radio-immunity. The number of IMP, and its distribution were analyzed with freeze-etching technique. Results The temperature of the amimals in heat stress raised rapidly; the biochemical indexes were abnormal obviously; the number of IMP, in intestinal epithelium decreased greatly with an obvious abnormal distribution and a wider effected area; the above indexes showed no notable signs of recovery whem heat stress stopped 4 to 24 hours. Conclusions (1) Heat stress could make cyto-membranous injury in a short time and the degree was in inverse ratio with the time of heat stress and the body temperature; (2)it would cause a massive release of such body-hurting substances as TxB2 and a reduce of body-protecting substances as PGFla;the indexes related to secondary lesion as CORT would keep on raising and TSA would show an abnormal increase. All these changes would finally result in extensive injury in general systems,many organs and cellular components. (3)The delayed injury was obvious.
