title: Luteinizing hormone receptors are expressed in rat myenteric neurons and mediate neuronal loss.
abstract: BACKGROUND
  Clinical observations have suggested repeated gonadotropin-releasing hormone (GnRH) exposure to cause intestinal dysfunction and loss of enteric neurons. This has been further studied and confirmed in a rat in vivo model involving iterated GnRH treatments. Mechanisms behind are enigmatic since no GnRH receptors are found to be expressed in enteric neurons neither in man nor rat. Both species, however, harbor substantial subpopulations of luteinizing hormone (LH) receptor-immunoreactive myenteric neurons which suggests that intestinal GnRH-induced neuropathy may be mediated by LH release.
  
  
  OBJECTIVE
  To reveal if exposures of GnRH or LH to rat myenteric neurons in vitro cause neuronal loss.
  
  
  METHODS
  Primary cultured adult rat myenteric neurons were exposed to single or repeated treatments of the GnRH analog buserelin or the LH analog lutrotropin alpha, and neuronal survival was determined by cell counting. Possible presence of GnRH- or LH receptor -immunoreactive neurons was determined by immunocytochemistry.
  
  
  RESULTS
  Exposure to the LH, but not the GnRH, analog caused significantly reduced neuronal survival. LH, but not GnRH, receptors were found to be expressed on cultured myenteric neurons.
  
  
  CONCLUSIONS
  Myenteric neurons express LH receptors in vitro and LH exposure causes reduced neuronal survival. This suggests that GnRH-induced enteric neuropathy in vivo is mediated by way of LH release and activation of enteric neuronal LH receptors.
authors.affiliation: Department of Experimental Medical Science, Unit Neurogastroenterology, BMC B11, Lund University, Sölvegatan 19, SE 22184 Lund, Sweden. Electronic address: elin.sand@med.lu.se.
authors.forename: Elin
authors.initials: E
authors.lastname: Sand
authors.affiliation: Department of Experimental Medical Science, Unit Neurogastroenterology, BMC B11, Lund University, Sölvegatan 19, SE 22184 Lund, Sweden. Electronic address: ulrikke.voss@med.lu.se.
authors.forename: Ulrikke
authors.initials: U
authors.lastname: Voss
authors.affiliation: Department of Clinical Sciences, Division of Internal Medicine, Lund University, Sweden Lund University, Inga Marie Nilssons gata 32, SE 21428 Malmö, Sweden. Electronic address: bodil.ohlsson@med.lu.se.
authors.forename: Bodil
authors.initials: B
authors.lastname: Ohlsson
authors.affiliation: Department of Experimental Medical Science, Unit Neurogastroenterology, BMC B11, Lund University, Sölvegatan 19, SE 22184 Lund, Sweden. Electronic address: eva.ekblad@med.lu.se.
authors.forename: Eva
authors.initials: E
authors.lastname: Ekblad
mesh_terms: D000818:Animals; D002064:Buserelin / Q000494:pharmacology; D002452:Cell Count; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives; D006728:Hormones / Q000494:pharmacology; D007082:Ileum / Q000294:innervation; D007150:Immunohistochemistry; D007986:Luteinizing Hormone / Q000031:analogs & derivatives; D008297:Male; D009197:Myenteric Plexus / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D017207:Rats, Sprague-Dawley; D011974:Receptors, LH / Q000378:metabolism*; D011966:Receptors, LHRH / Q000378:metabolism
chemical_list: D006728:Hormones; D011974:Receptors, LH; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone; D007986:Luteinizing Hormone; D002064:Buserelin
keywords: Enteric nervous system (ENS); Gonadotropin-releasing hormone (GnRH); Luteinizing hormone; Primary cultures of enteric neurons