title: Opioid peptide mRNA expression in the colon of the rat.
abstract: Since the discovery of opioid peptides, several immunohistochemical and radioimmunological studies have demonstrated their localization in the gastrointestinal tract without demonstrating the localization of their common precursor. The present study describes the distribution and the colocalization of proenkephalin and prodynorphin messenger RNAs (mRNAs) in the colon of rat by in situ hybridization. Proenkephalin and prodynorphin mRNAs were found in myenteric plexus, but not in the submucous plexus or in the mucosa. In myenteric plexus, the number of neurons expressing proenkephalin is 2.5 times greater than that of the neurons expressing only prodynorphin. Furthermore, double in situ hybridization histochemistry indicates that at least three groups of opioid neurons can be distinguished, those containing proenkephalin and prodynorphin mRNAs together, and those containing only proenkephalin mRNA or only prodynorphin mRNA.
authors.affiliation: Department of Neurophysiology, CNRS ESA 6034, Faculté des Sciences de Saint-Jérôme 13397, Marseille, France.
authors.forename: C
authors.initials: C
authors.lastname: Porcher
authors.forename: D
authors.initials: D
authors.lastname: Bagnol
authors.forename: S J
authors.initials: SJ
authors.lastname: Watson
mesh_terms: D000818:Animals; D001345:Autoradiography; D003106:Colon / Q000378:metabolism*; D004745:Enkephalins / Q000235:genetics*; D017403:In Situ Hybridization; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004745:Enkephalins; D011498:Protein Precursors; D012333:RNA, Messenger; C029992:proenkephalin; C033660:preproenkephalin