1. Evidence for the presence of motilin, ghrelin, and the motilin and ghrelin receptor in neurons of the myenteric plexus
- Author
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Inge Depoortere, Michele Zandecki, Ming Tang, Theo L. Peeters, Catherine Tomasetto, Luo Xu, Jean-Pierre Timmermans, Institut de génétique et biologie moléculaire et cellulaire (IGBMC), and Université Louis Pasteur - Strasbourg I-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Male ,Receptors, Neuropeptide ,Physiology ,Peptide Hormones ,Motilin receptor ,Clinical Biochemistry ,Growth hormone secretagogue receptor ,MESH: Neurons ,MESH: Receptors, G-Protein-Coupled ,Biochemistry ,Receptors, G-Protein-Coupled ,0302 clinical medicine ,Endocrinology ,MESH: Reverse Transcriptase Polymerase Chain Reaction ,MESH: Blotting, Southern ,MESH: Animals ,Receptors, Ghrelin ,Receptor ,Myenteric plexus ,Neurons ,MESH: Choline O-Acetyltransferase ,Reverse Transcriptase Polymerase Chain Reaction ,MESH: Receptors, Neuropeptide ,MESH: Motilin ,digestive, oral, and skin physiology ,Immunohistochemistry ,Choline acetyltransferase ,Ghrelin ,Blotting, Southern ,Female ,030211 gastroenterology & hepatology ,MESH: Nitric Oxide Synthase ,hormones, hormone substitutes, and hormone antagonists ,medicine.medical_specialty ,Guinea Pigs ,Myenteric Plexus ,Biology ,Choline O-Acetyltransferase ,Receptors, Gastrointestinal Hormone ,Motilin ,MESH: Guinea Pigs ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,Internal medicine ,medicine ,Animals ,RNA, Messenger ,MESH: Myenteric Plexus ,MESH: RNA, Messenger ,MESH: Receptors, Gastrointestinal Hormone ,MESH: Immunohistochemistry ,[SDV.BBM.BM]Life Sciences [q-bio]/Biochemistry, Molecular Biology/Molecular biology ,MESH: Male ,nervous system ,MESH: Peptide Hormones ,Enteric nervous system ,Nitric Oxide Synthase ,MESH: Female ,030217 neurology & neurosurgery - Abstract
Motilin, a 22-amino acid gastrointestinal peptide, and ghrelin, the natural ligand of the growth hormone secretagogue receptor, form a new group of structurally related peptides. Several lines of evidence suggest that motilin and ghrelin are involved in the control of gastrointestinal motility by the activation of receptors on enteric neurons. The aim of this study was to look for the existence of motilin, ghrelin, and their respective receptors in the myenteric plexus of the guinea pig. We used longitudinal muscle/myenteric plexus (LMMP) preparations and cultures of myenteric neurons of the guinea pig ileum, immunohistochemistry, and reverse transcriptase-polymerase chain reaction (RT-PCR). Most of the motilin-immunoreactive (IR; 72.8%) and motilin receptor-IR (68.9%) neurons were also positive for neuronal nitric oxide synthase (nNOS), 72.8% and 68.9%, few for choline acetyl transferase (ChAT), 11.4% and 11.9%, respectively. In contrast, ghrelin was mainly colocalized with ChAT (72.2%), and only 3.6% of ghrelin-positive cells showed nNOS-IR in the LMMP. Neither motilin nor the motilin receptor or ghrelin colocalized with calbindin. RT-PCR studies revealed motilin, ghrelin, and ghrelin receptor mRNA transcripts in LMMP preparations and in cultured myenteric neurons. In conclusion, this study, for the first time, provides direct evidence for the existence of motilin and ghrelin in myenteric neurons and suggests that both peptides may play a role in the activation of the enteric nervous system and hence in the regulation of gastrointestinal motility.
- Published
- 2005