title: Expression of OP4 (ORL1, NOP1) receptors in vascular endothelium.
abstract: Endothelial cells from rat brain microvessels, human aortic artery and human umbilical vein were examined, together with ex vivo rat brain capillaries and rat aortic ring sections, for the expression of opioid receptor-like OP-4 mRNA and protein. High levels of mRNA expression and an immunopositive reaction for the receptor protein were detected in the endothelial cells from primary and from established in vitro cultures, as well as in the intima of ex vivo rat aortic rings, where the signal was limited to the endothelial layer. Interaction of the OP4 receptor with its physiological ligand nociceptin caused, in cultured endothelial cells, the activation of a mitogen-activated protein (MAP) kinase cascade. Taken together, these results show that the OP4 receptor is synthesised and functionally expressed in endothelial cells, presumably as a starting point for some vasoactive mechanism(s).
authors.affiliation: Department of Cell Biology and Development, University of Rome La Sapienza, Rome, Italy.
authors.forename: Filippo
authors.initials: F
authors.lastname: Granata
authors.forename: Rossella Luisa
authors.initials: RL
authors.lastname: Potenza
authors.forename: Anna
authors.initials: A
authors.lastname: Fiori
authors.forename: Roberto
authors.initials: R
authors.lastname: Strom
authors.forename: Brunella
authors.initials: B
authors.lastname: Caronti
authors.forename: Paola
authors.initials: P
authors.lastname: Molinari
authors.forename: Sonia
authors.initials: S
authors.lastname: Donsante
authors.forename: Gennaro
authors.initials: G
authors.lastname: Citro
authors.forename: Luisa
authors.initials: L
authors.lastname: Iacovelli
authors.forename: Antonio
authors.initials: A
authors.lastname: De Blasi
authors.forename: Richard T
authors.initials: RT
authors.lastname: Ngomba
authors.forename: Guido
authors.initials: G
authors.lastname: Palladini
authors.forename: Francesca
authors.initials: F
authors.lastname: Passarelli
mesh_terms: D000818:Animals; D001013:Aorta, Thoracic / Q000737:chemistry / Q000378:metabolism; D001921:Brain / Q000378:metabolism; D019556:COS Cells; D002352:Carrier Proteins / Q000096:biosynthesis / Q000502:physiology; D002522:Chlorocebus aethiops; D004730:Endothelium, Vascular / Q000737:chemistry / Q000378:metabolism*; D005656:Fungal Proteins / Q000096:biosynthesis / Q000502:physiology; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D008297:Male; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D011957:Receptors, Opioid / Q000096:biosynthesis* / Q000502:physiology; D000094942:Nociceptin Receptor
chemical_list: D002352:Carrier Proteins; D005656:Fungal Proteins; C401582:NOP-1 protein, Neurospora crassa; D012333:RNA, Messenger; D011957:Receptors, Opioid; D000094942:Nociceptin Receptor