Subjects: Biology >> Zoology submitted time 2017-10-11 Cooperative journals: 《动物营养学报》
Abstract：本试验旨在研究不同水平玉米赤霉烯酮(ZEA)污染饲粮对断奶小母猪卵巢指数及孕激素受体的阳性分布和mRNA表达量的影响。选择40头25~28日龄健康三元杂交（杜×长×大）断奶小母猪按平均体重[（14.01±0.86） kg]随机分为4个组，采用单笼饲养。对照组饲喂基础饲粮，试验组分别在基础饲粮中添加0.5、1.0和1.5 mg/kg的ZEA，4个组ZEA的测定值分别为0、（0.52±0.07）、（1.04±0.03）和（1.51±0.13） mg/kg。预饲10 d，正试期35 d。结果表明：随着饲粮ZEA水平的升高，断奶小母猪卵巢指数呈一次线性升高（P<0.01）；1.0 mg/kg ZEA组的卵巢指数显著高于1.5 mg/kg ZEA组（P<0.05），1.5 mg/kg ZEA组的卵巢指数显著高于0.5 mg/kg ZEA组和对照组（P<0.05）。随着饲粮ZEA水平的升高，断奶小母猪卵巢孕激素受体累积光密度（IOD）和mRNA相对表达量均呈一次线性升高（P<0.01）；1.5 mg/kg ZEA组的孕激素受体IOD和mRNA相对表达量显著高于1.0 mg/kg ZEA组（P<0.05），1.0 mg/kg ZEA组又显著高于0.5 mg/kg ZEA组和对照组（P<0.05）。免疫组化结果显示断奶小母猪卵巢中孕激素受体免疫阳性物质主要分布于原始卵泡和生长卵泡的卵母细胞及颗粒细胞、卵泡膜细胞及血管壁细胞。随着饲粮ZEA水平的升高和卵泡闭锁程度的增加，免疫阳性反应明显增强，但卵巢内孕激素受体免疫阳性物质的分布位置没有因ZEA的水平发生明显改变。由此可见，ZEA（1.0～1.5 mg/kg）可以通过调控断奶小母猪卵巢中孕激素受体的高水平表达，使孕激素受体的水平超出正向调节卵泡生长的限值，从而促使卵泡闭锁，降低卵巢指数，改变卵巢发育，进而影响断奶小母猪生殖系统的健康。
Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》
Abstract： The aims of the present study were to investigate the effects of zearalenone on ovary index, distribution and mRNA expression of progesterone receptors in ovaries of weaned gilts. Forty healthy weaned piglets (Duroc×Landrace×Large White) aged of 25 to 28 days were allocated into 4 groups according to the average body weight [(14.01 ± 0.86) kg]. Animals were fed individually in a metabolic cage for 35 days after 10 days adaptation. Piglets in the control group were fed a basal diet, and in experimental groups were fed basal diets supplemented with 0.5, 1.0 and 1.5 mg/kg ZEA, respectively. The analyzed ZEA levels in four groups were 0, （0.52±0.07）, （1.04±0.03） and （1.51±0.13） mg/kg. The results indicated that ovary index showed a linear increase (P<0.01) with the ZEA level increasing in the diet of weaned gilts. The ovary index in 1.0 mg/kg ZEA group was significantly higher than that in 1.5 mg/kg ZEA group (P<0.05), and the ovary index in 1.5 mg/kg ZEA group was significantly higher than that in 0.5 mg/kg ZEA group and the control group (P<0.05). The integrated optical density (IOD) and mRNA relative expression of progesterone receptors in ovaries of weaned gilts showed a linear increase (P<0.01) with the ZEA level increasing in the diet of weaned gilts. The IOD and mRNA relative expression of progesterone receptors in 1.5 mg/kg ZEA group was significantly higher than that in 1.0 mg/kg ZEA group, and the IOD and mRNA relative expression of progesterone receptors in 1.0 mg/kg ZEA group was significantly higher than that in 0.5 mg/kg ZEA group and the control group (P<0.05). The results of immunohistochemistry showed that the immunoreactive substance of progesterone receptors in ovaries was mainly distributed in oocytes and granulosa cells, theca cells and vascular wall cells of primordial follicles and growing follicles. With the increase of ZEA level and the degree of follicular atresia, immunoreactivity was significantly enhanced. There was no significant change in the distribution of immunoreactive substance of progesterone receptors in the ovary, due to the presence of ZEA. Thus it can be seen that ZEA (1.0 to 1.5 mg/kg) in feed changes the development of ovary by up-regulating the expression of progesterone receptors. The levels of progesterone receptors exceed the limit of positive regulation of follicular growth, thus promoting follicular atresia, reducing the ovary index, and then the healthy of reproductive system is affected.
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