镰刀菌毒素对断奶仔猪子宫组织结构、Hsp70分布和表达的影响

Effect of Dietary Fusarium Toxin on Histological Structure,Distribution and Expression of Hsp70 in the Uterus of Post-Weaning Piglets

本研究旨在探讨镰刀菌毒素对断奶仔猪子宫的组织结构、Hsp70的分布和mRNA表达量的影响。选择35日龄体重为(8.45±0.94)kg的健康三元杂交(杜洛克×长白×大白)雌性断奶仔猪20头,仔猪随机分为2组,每组10头。对照组饲喂基础饲粮,镰刀菌毒素组饲喂含有镰刀菌毒素(玉米赤霉烯酮0.90mg·kg^(-1),呕吐毒素1.43mg·kg^(-1),烟曲霉毒素5.85mg·kg^(-1))的试验饲粮,预试期7d,正试期35d,试验结束进行屠宰取出子宫。结果表明:与对照组相比,镰刀菌毒素极显著降低了仔猪的平均日增重和平均日采食量(P<0.01),引起子宫器官指数极显著增加(对照组:0.91±0.03,镰刀菌毒素组:1.90±0.10,P<0.01),子宫腺腺泡数量增多、密度增大,子宫内膜厚度极显著增加(对照组:1 002.55±101.22μm,镰刀菌毒素组:1 343.09±104.57μm,P<0.01)。肌层增厚一倍以上(对照组:355.58±28.26μm,镰刀菌毒素组:779.56±40.38μm),与对照组相比均差异极显著(P<0.01)。子宫中的Hsp70阳性细胞主要分布在子宫内膜上皮和子宫腺柱状上皮内,为胞质着色。与对照组相比,镰刀菌毒素组子宫Hsp70的免疫阳性反应明显增强(P<0.01),且内环肌层也可见有Hsp70阳性细胞存在,子宫腺上皮细胞Hsp70IOD较对照组增加2倍多。镰刀菌毒素组子宫Hsp70mRNA相对表达量显著高于对照组(P<0.05)。综上表明,本试验条件下,镰刀菌毒素可引起断奶仔猪子宫氧化应激反应,子宫内膜上皮和子宫腺上皮通过增加自分泌Hsp70能力,一定限度内能够对抗镰刀菌毒素对子宫正常生理机能的影响。

The present study was aimed at investigating the effects of fusarium toxins on histologi- cal structure, HspT0 distribution and mRNA expression levels in the uterus of post-weaning pig- lets. A total of 20 healthy post-weaning piglets （DurocX LandraceN Large White） weaned at 35 d with an average body weight （（8.45±0.94）kg）were randomly allocated into 2 treatments with 10 in the control group and 10 in the fusarium toxins group. Piglets of the control group were fed a based diet only, and piglets of the fusarium toxins group were fed test diet containing fusarium toxin （0.90 mg ~ kg-1 ZEN, 1.43 mg ~ kg-~ DON, 5.85 mg ~ kg-1 FUM） for 35 d after 7 d ad- aptation. Results showed that the average daily feed intake and average daily gain of piglets of the fusarium group were decreased significantly （P^0.01）, however, the uterine organ index （con- trol group： 0.91!0.03, fusarium toxins group. 1.90~0.10）, the number and density of uterine glandular acini and the thickness of endometrium of postweaning piglets （control group. 1 002.55~101.22 /~m, fusarium toxins group： 1 343.09~104.57 ~m, P^0.01） were increased significantly, the thickeness of the myometrium was more than doubled that of the control group （control group： 355.58 ~ 28. 26 ~tm, fusarium toxins group. 779. 56 ~ 40. 38 ~m, P^0.01）, these were extremly significant difference in comparison with the control group （P^0.01）. The observation result of Hsp70 immunoreactive cells revealed that Hsp70 were mainly distributed in the cytoplasm of the endometrium epithelium and columnar glandular epithelium. Compared with the control group, the Hsp70 immunoreactivity of the fusarium toxins group was enhanced obvi- ously （P^O. 01）, as well as Hsp70 positive ceils of the fusarium toxins group were also found in the inner circular muscle layer of the uterus, and the IOD of Hsp70 in the uterine glandular epi- thelial ceils was 2 times higher than that of the control group （P^0.01）. The relative expression of Hsp70 mRNA in the fusarium toxins group was significantly higher than that of the control group （P%0.05）. In conclusion, the present study found that the fusarium toxins could cause the oxidative stress of the uterus in post-weaning piglets, and this results suggested that the en- dometrial epithelium and columnar glandular epithelium could resist the effects of fusarium toxins on the normal physiological function of the uterus within a certein degree by incereasing its auto- crine ability of HSP70 in piglet uterus.