不同水平玉米赤霉烯酮对断奶仔猪卵巢发育的影响

Effects of different levels of zearalenone on the ovarian development of weaning piglets

为了研究不同水平玉米赤霉烯酮(zearalenone,ZEA)对断奶仔猪卵巢发育的影响,选择40头健康三元杂交(杜×长×大)断奶雌性仔猪,体质量(14.01±0.86)kg,随机分为4组,每组10头。对照组饲喂基础饲粮,3个试验组分别在基础饲粮基础上添加0.5(ZEA0.5)、1.0(ZEA1.0)和1.5(ZEA1.5)mg/kg的ZEA。预试期10d,正试期35d。组织学观察发现,添加ZEA后仔猪卵巢组织结构发生改变,各处理组原始卵泡明显减少,生长卵泡明显增多,ZEA1.5组生长卵泡多发生闭锁。免疫组化、RT-PCR和Western blot检测结果显示,添加不同水平ZEA后卵巢中PCNA、Bax及Bcl-2表达出现明显的异常;PCNA和Bax表达量显著上调,且ZEA1.0组高于ZEA0.5组,其次是ZEA1.5组;而Bcl-2的表达量呈剂量依赖性减少,ZEA1.0和1.5组与对照组相比差异极显著(P<0.01)。结果表明:饲粮添加0.5~1.5mg/kg ZEA可引起断奶仔猪卵巢的卵泡提前发育甚至闭锁,主要途径是诱导PCNA、Bcl-2及Bax基因异常表达,引起卵巢卵泡异常发育。

In order to study the influence of different levels of zearalenone(ZEA)contaminated diets on the ovary development of weaned piglets,40 healthy(Duroc×Landrace×Large White)weaned piglets(14.01±0.86)kg were selected and randomly divided into 4 groups,10 piglets per each group.The control group was fed the normal basal diet(Control),three treatment groups were fed the normal basal diet supplemented with 0.5(ZEA0.5),1.0(ZEA1.0)and 1.5(ZEA 1.5)ZEA mg/kg.The piglets were fed for 35 dafter the 10 dadaptation.The result showed that the histology structure of ovary was changed,and the number of primordial follicles were decreased significantly,the number of primary growth follicles and secondary growth follicles were increased significantly.But lots of follicles revealed the atresia trend and these atresia follicles were increased significantly in the ZEA1.5 treatment group.The results of immunohistochemistry,RT-PCR and Western blot showed that the expression of PCNA,Bax and Bcl-2 in ovary were obvious abnormality after adding ZEA.Compared with the control group,the expression of PCNA and Bax were significantly up-regulated and ZEA1.0 group was higher than ZEA0.5 group,followed by ZEA1.5 group.The expression of Bcl-2 were decreased significantly in a dose-dependent manner and ZEA1.0 and 1.5 groups was significantly lower than that in the control group(P<0.01).These results suggested that ZEA(0.5-1.5 mg/kg)could induce or promote the advanced development of follicles and even atresia,indicating that ZEA could induce abnormal expression of PCNA,Bcl-2 and Bax,then caused the follicles abnormal development in ovary.