Effects of Orexin A on mRNA Expression of Various Neuropeptides in the Hypothalamus and Pituitary, and on Serum LH Levels in Ovariectomized Gilts

作     者：NING Hong-mei GE Ya-ming SU Juan ZHANG Wen-long YAO Yuan YANG Gui-hong LEI Zhi-hai 

作者机构：College of Veterinary Medicine Nanjing Agricultural University Nanjing 210095 P.R.China College of Animal Science Henan Institute of Science and Technology Xinxiang 453003 P.R.China 

出 版 物：《Agricultural Sciences in China》 (中国农业科学（英文版）)

年 卷 期：2010年第9卷第9期

页      面：1362-1371页

核心收录：

学科分类：0710[理学-生物学] 090602[农学-预防兽医学] 071010[理学-生物化学与分子生物学] 081704[工学-应用化学] 07[理学] 08[工学] 0817[工学-化学工程与技术] 09[农学] 0906[农学-兽医学] 0901[农学-作物学] 0902[农学-园艺学] 

基　　金：sponsored by the National Natural Sci-ence Foundation of China (30471248) 

主　　题：orexin A OVX gilt relative neuropeptides LH hypothalamus pituitary 

摘      要：Orexin has several biological functions, including the regulation of reproductive endocrine signaling, which has received much attention. However, little is known about the mechanism through which orexin regulates the levels of neuroendocrine hormones and peptides. We injected orexin A or physiological saline into the lateral ventricle of 10 ovariectomized （OVX） gilts, and determined the subsequent changes in serum luteinizing hormone （LH） concentration by using radioimmunoassay （RIA）. We also examined the expression of GnRH, NPY, and POMC mRNAs in the hypothalamus and that of LH, folliclestimulating hormone （FSH）, POMC, and ghrelin mRNAs in the pituitary by using semi-quantitative reverse transcription polymerase chain reaction. We found the following results： （1） Orexin A transiently promoted LH secretion; serum LH concentration started to increase at 10 min after the orexin injection, peaked at 30 min, and returned to its initial level at 1.5 h; （2） orexin A upregulated GnRH mRNA expression and downregulated NPY and POMC mRNAs expression in the hypothalamus; （3） orexin A upregulated LH and FSH mRNAs expression （FSH, P〉 0.05）, but downregulated ghrelin mRNA expression in the pituitary. No significant effects were observed on the pituitary expression of FSH and POMC mRNAs. Our data suggest that orexin A regulates reproductive function by stimulating GnRH and LH release directly and indirectly via its effects on NPY, POMC and ghrelin expression.