Fan Juexin, Zhang Bin, Li Lili, Xiao Chaowu, Oladele Oso Abimbola, Jiang Guoli, Ding Hao, Wang Shengping, Xing Yueteng, Xiao Dingfu, Yin Yulong
College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China ; Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Hunan Provincial Engineering Research Center of Healthy Livestock, Key Laboratory for Agro-Ecological Processes of Subtropical Region, Institute of Subtropical Agriculture, The Chinese Academy of Sciences, Changsha, 410125, China.
College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China.
Asian-Australas J Anim Sci. 2015 Nov;28(11):1573-82. doi: 10.5713/ajas.15.0185.
This study was to investigate the effect of soyabean isoflavones (SIF) on onset of puberty, serum hormone concentration, and gene expression in hypothalamus, pituitary and ovary of female Bama miniature pigs. Fifty five, 35-days old pigs were randomly assigned into 5 treatment groups consisting of 11 pigs per treatment. Results showed that dietary supplementation of varying dosage (0, 250, 500, and 1,250 mg/kg) of SIF induced puberty delay of the pigs with the age of puberty of pigs fed basal diet supplemented with 1,250 mg/kg SIF was significantly higher (p<0.05) compared to control. Supplementation of SIF or estradiol valerate (EV) reduced (p<0.05) serum gonadotrophin releasing hormone and luteinizing hormone concentration, but increased follicle-stimulating hormone concentration in pigs at 4 months of age. The expression of KiSS-1 metastasis-suppressor (KISS1), steroidogenic acute regulatory protein (StAR) and 3-beta-hydroxysteroid dehydrogenase/delta-5-delta-4 isomerase (3β-HSD) was reduced (p<0.01) in SIF-supplemented groups. Expression of gonadotropin-releasing hormone receptor in the pituitary of miniature pigs was reduced (p<0.05) compared to the control when exposed to 250, 1,250 mg/kg SIF and EV. Pigs on 250 mg/kg SIF and EV also showed reduced (p<0.05) expression of cytochrome P450 19A1 compared to the control. Our results indicated that dietary supplementation of SIF induced puberty delay, which may be due to down-regulation of key genes that play vital roles in the synthesis of steroid hormones.
本研究旨在探讨大豆异黄酮（SIF）对雌性巴马小型猪青春期启动、血清激素浓度以及下丘脑、垂体和卵巢基因表达的影响。55头35日龄仔猪被随机分为5个处理组，每组11头。结果显示，日粮中添加不同剂量（0、250、500和1250mg/kg）的SIF会导致仔猪青春期延迟，与对照组相比，添加1250mg/kg SIF的基础日粮喂养的仔猪青春期年龄显著更高（p<0.05）。添加SIF或戊酸雌二醇（EV）可降低（p<0.05）4月龄仔猪血清促性腺激素释放激素和促黄体生成素浓度，但会增加促卵泡生成素浓度。在添加SIF的组中，转移抑制基因KiSS-1（KISS1）、类固醇生成急性调节蛋白（StAR）和3-β-羟基类固醇脱氢酶/δ5-δ4异构酶（3β-HSD）的表达降低（p<0.01）。与对照组相比，当暴露于250、1250mg/kg SIF和EV时，小型猪垂体中促性腺激素释放激素受体的表达降低（p<0.05）。与对照组相比，日粮添加250mg/kg SIF和EV的仔猪细胞色素P450 19A1的表达也降低（p<0.05）。我们的结果表明，日粮添加SIF会导致青春期延迟，这可能是由于在类固醇激素合成中起关键作用的基因下调所致。
