Expression of OP4 (ORL1, NOP1) receptors in vascular endothelium.
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).
Granata
Filippo
F
Department of Cell Biology and Development, University of Rome La Sapienza, Rome, Italy.
Potenza
Rossella Luisa
RL
Fiori
Anna
A
Strom
Roberto
R
Caronti
Brunella
B
Molinari
Paola
P
Donsante
Sonia
S
Citro
Gennaro
G
Iacovelli
Luisa
L
De Blasi
Antonio
A
Ngomba
Richard T
RT
Palladini
Guido
G
Passarelli
Francesca
F
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
D002352:Carrier Proteins; D005656:Fungal Proteins; C401582:NOP-1 protein, Neurospora crassa; D012333:RNA, Messenger; D011957:Receptors, Opioid; D000094942:Nociceptin Receptor