Expression of feeding-related peptide receptors mRNA in GT1-7 cell line and roles of leptin and orexins in control of GnRH secretion

• 来源期刊: 中国药理学报（英文版）
• 关键词: GT1-7 cell line bombesin cholecystokinin neuropeptide Y neurotensin orexin leptin gonadorelin
• 年，卷（期）: 2005,（8）
• 页码范围: 976-981
• 页数: 6页
• 语种: 英文

摘要

Aim: To investigate the expression of feeding-related peptide receptors mRNA in GT1-7 cell line and roles of leptin and orexins in the control of GnRH secretion.Methods: Receptors of bombesin3, cholecystokinin (CCK)-A, CCK-B, glucagonlike peptide (GLP)1, melanin-concentrating hormone (MCH)1, orexinl, orexin2,neuromedin-B, neuropeptide Y (NPY) 1 and NPY5, neurotensin (NT) 1, NT2, NT3,and leptin receptor long form mRNA in GT1-7 cells were detected by reversed transcriptase-polymerase chain reaction. GT1-7 cells were treated with leptin,orexin A and orexin B at a cohort of concentrations for different lengths of time,and GnRH in medium was determined by radioimmunoassay (RIA). Results:Receptors of bombesin 3, CCK-B, GLP1, MCH1, orexinl, neuromedin-B, NPY1,NPY5, NT1, NT3, and leptin receptor long form mRNA were expressed in GT1-7cells, of which, receptors of GLP1, neuromedin-B, NPY1, and NT3 were highly expressed. No amplified fragments of orexin2, NT2, and CCK-A receptor cDNA were generated with GT1-7 RNA, indicating that the GT1-7 cells did not express mRNA of them. Leptin induced a significant stimulation of GnRH release, the results being most significant at 0.1 nmol/L for 15 min. In contrast to other studies in hypothalamic explants, neither orexin A nor orexin B affected basal GnRH secretion over a wide range of concentrations ranging from 1 nmol/L to 500 nmol/Lat 15, 30, and 60 min. Conclusion: Feeding and reproductive function are closely linked. Many orexigenic and anorexigenic signals may control feeding behavior as well as alter GnRH secretion through their receptors on GnRH neurons.