title: Effect of Soyabean Isoflavones Exposure on Onset of Puberty, Serum Hormone Concentration and Gene Expression in Hypothalamus, Pituitary Gland and Ovary of Female Bama Miniature Pigs.
abstract: 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.
authors.affiliation: 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.
authors.forename: Juexin
authors.initials: J
authors.lastname: Fan
authors.affiliation: College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Zhang
authors.affiliation: 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.
authors.forename: Lili
authors.initials: L
authors.lastname: Li
authors.affiliation: Nutrition Research Division, Food Directorate, Health Canada, Ottawa, Ontario, K1A 0K9, Canada.
authors.forename: Chaowu
authors.initials: C
authors.lastname: Xiao
authors.affiliation: Department of Animal Nutrition, College of Animal Science and Livestock Production, Federal University of Agriculture, Abeokuta, PMB2240, Nigeria.
authors.forename: Oso Abimbola
authors.initials: OA
authors.lastname: Oladele
authors.affiliation: 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.
authors.forename: Guoli
authors.initials: G
authors.lastname: Jiang
authors.affiliation: 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.
authors.forename: Hao
authors.initials: H
authors.lastname: Ding
authors.affiliation: 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.
authors.forename: Shengping
authors.initials: S
authors.lastname: Wang
authors.affiliation: 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.
authors.forename: Yueteng
authors.initials: Y
authors.lastname: Xing
authors.affiliation: College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China.
authors.forename: Dingfu
authors.initials: D
authors.lastname: Xiao
authors.affiliation: 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.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Yin
keywords: Bama Miniature Pigs; Puberty; Puberty Delay; Soybean Isoflavones