title: Expression of feeding-related peptide receptors mRNA in GT1-7 cell line and roles of leptin and orexins in control of GnRH secretion.
abstract: OBJECTIVE
  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, glucagon-like peptide (GLP)1, melanin-concentrating hormone (MCH)1, orexin1, 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, orexin1, neuromedin-B, NPY1, NPY5, NT1, NT3, and leptin receptor long form mRNA were expressed in GT1-7 cells, 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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Rui-jin Hospital Affiliated to Shanghai Second Medical University, Shanghai Institute of Endocrine and Metabolic Diseases, Shanghai 200025, China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Yang
authors.forename: Li-bin
authors.initials: LB
authors.lastname: Zhou
authors.forename: Shang-quan
authors.initials: SQ
authors.lastname: Liu
authors.forename: Jing-feng
authors.initials: JF
authors.lastname: Tang
authors.forename: Feng-yin
authors.initials: FY
authors.lastname: Li
authors.forename: Rong-ying
authors.initials: RY
authors.lastname: Li
authors.forename: Huai-dong
authors.initials: HD
authors.lastname: Song
authors.forename: Ming-dao
authors.initials: MD
authors.lastname: Chen
mesh_terms: D000818:Animals; D002460:Cell Line; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000235:genetics; D015870:Gene Expression; D000067757:Glucagon-Like Peptide-1 Receptor; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins / Q000494:pharmacology; D020738:Leptin / Q000494:pharmacology*; D009479:Neuropeptides / Q000494:pharmacology*; D064446:Orexin Receptors; D000068797:Orexins; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D011863:Radioimmunoassay; D043887:Receptor, Cholecystokinin B / Q000235:genetics; D018004:Receptors, Bombesin / Q000235:genetics; D011956:Receptors, Cell Surface / Q000235:genetics; D043562:Receptors, G-Protein-Coupled; D018027:Receptors, Glucagon / Q000235:genetics; D054411:Receptors, Leptin; D018013:Receptors, Neuropeptide / Q000235:genetics; D017476:Receptors, Neuropeptide Y / Q000235:genetics; D018028:Receptors, Neurotensin / Q000235:genetics; D018000:Receptors, Peptide / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors
chemical_list: D000067757:Glucagon-Like Peptide-1 Receptor; D047908:Intracellular Signaling Peptides and Proteins; D020738:Leptin; D009479:Neuropeptides; D064446:Orexin Receptors; D000068797:Orexins; D012333:RNA, Messenger; D043887:Receptor, Cholecystokinin B; D018004:Receptors, Bombesin; D011956:Receptors, Cell Surface; D043562:Receptors, G-Protein-Coupled; D018027:Receptors, Glucagon; D054411:Receptors, Leptin; D018013:Receptors, Neuropeptide; D017476:Receptors, Neuropeptide Y; D018028:Receptors, Neurotensin; D018000:Receptors, Peptide; C107120:bombesin receptor subtype 3; D007987:Gonadotropin-Releasing Hormone