title: Nociceptin, an endogenous ligand for the ORL1 receptor, decreases cardiac output and total peripheral resistance in the rat.
abstract: The heptadecapeptide nociceptin, also known as Orphanin FQ, is a newly discovered endogenous ligand for the opioid-like G-protein coupled receptor, ORL1. In the present study, responses to intravenous injections of nociceptin were investigated in the systemic vascular bed of the rat. Nociceptin induced dose-related decreases in systemic arterial pressure and total peripheral resistance when injected in doses of 1-30 nmol/kg i.v.. Nociceptin decreased heart rate and in doses of 10 and 30 nmol/kg i.v., significantly decreased cardiac output. In terms of relative vasodilator activity, nociceptin was approximately 10-fold less potent than the beta-adrenergic receptor agonist isoproterenol. These data show that nociceptin has novel vasodilator activity in the systemic vascular bed of the rat.
authors.affiliation: Department of Pharmacology, Tulane University School of Medicine, New Orleans, Louisiana 70112, USA.
authors.forename: H C
authors.initials: HC
authors.lastname: Champion
authors.forename: M A
authors.initials: MA
authors.lastname: Czapla
authors.forename: P J
authors.initials: PJ
authors.lastname: Kadowitz
mesh_terms: D053607:Adrenomedullin; D000595:Amino Acid Sequence; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D007275:Injections, Intravenous; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008969:Molecular Sequence Data; D018847:Opioid Peptides / Q000008:administration & dosage / Q000502:physiology*; D010455:Peptides / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D011957:Receptors, Opioid / Q000819:agonists / Q000187:drug effects / Q000378:metabolism*; D014655:Vascular Resistance / Q000187:drug effects*; D000094942:Nociceptin Receptor; D000097629:Nociceptin
chemical_list: D053607:Adrenomedullin; D007545:Isoproterenol; D018847:Opioid Peptides; D010455:Peptides; D011957:Receptors, Opioid; D000094942:Nociceptin Receptor; D000097629:Nociceptin; C000722285:Oprl1 protein, rat