title: Elevation of plasma noradrenaline levels in urethane-anaesthetized rats by activation of central prostanoid EP3 receptors.
abstract: 1. We studied the effects of intracerebroventricular (i.c.v.) administration of prostaglandin E2 (PGE2) and its receptor subtype ligands on plasma levels of catecholamines in urethane-anaesthetized rats. 2. Administration of PGE2 (0.15, 0.3 and 1.5 nmol per animal, i.c.v.) dose-dependently elevated plasma levels of noradrenaline (NA), while the levels of adrenaline were not affected. 3. Administration of sulprostone (EP3/EP1 agonist) and misoprostol (EP3/EP2 agonist) effectively elevated plasma NA levels in a dose-dependent manner (0.1, 0.3, and 1.0 nmol per animal). Butaprost (EP2 agonist) (0.3, 1.0 and 3.0 nmol per animal) was without effect. 17-Phenyl-omega-trinor PGE2 (EP1/EP3 agonist) effectively elevated plasma NA levels only at its highest dose (1.0 nmol per animal), but this elevation was not attenuated by pretreatment with SC-19220 (selective EP1 antagonist) (20 nmol per animal, i.c.v.). 4. The potency of these test agents in elevating plasma levels of NA was as follows; misoprostol > sulprostone > PGE2 > > 17-phenyl-omega-trinor PGE2 > > > butaprost. These results suggest that activation of central prostanoid EP3-receptors induces central sympathetic outflow in rats.
authors.affiliation: Department of Pharmacology, Kochi Medical School, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yokotani
authors.forename: M
authors.initials: M
authors.lastname: Nishihara
authors.forename: Y
authors.initials: Y
authors.lastname: Murakami
authors.forename: T
authors.initials: T
authors.lastname: Hasegawa
authors.forename: Y
authors.initials: Y
authors.lastname: Okuma
authors.forename: Y
authors.initials: Y
authors.lastname: Osumi
mesh_terms: D000020:Abortifacient Agents, Nonsteroidal / Q000008:administration & dosage / Q000494:pharmacology; D000527:Alprostadil / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D018686:Anesthetics, Intravenous; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D012531:Dibenz(b,f)(1,4)oxazepine-10(11H)-carboxylic acid, 8-chloro-, 2-acetylhydrazide / Q000008:administration & dosage / Q000494:pharmacology; D015237:Dinoprost / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology; D015232:Dinoprostone / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D007276:Injections, Intraventricular; D008297:Male; D016595:Misoprostol / Q000008:administration & dosage / Q000494:pharmacology; D009638:Norepinephrine / Q000097:blood*; D011448:Prostaglandin Antagonists / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018078:Receptors, Prostaglandin E / Q000819:agonists*; D014520:Urethane
chemical_list: D000020:Abortifacient Agents, Nonsteroidal; D018686:Anesthetics, Intravenous; D011448:Prostaglandin Antagonists; D018078:Receptors, Prostaglandin E; D016595:Misoprostol; C088173:17-phenyl-18,19,20-trinor-prostaglandin F2 alpha-1-isopropyl ester; D012531:Dibenz(b,f)(1,4)oxazepine-10(11H)-carboxylic acid, 8-chloro-, 2-acetylhydrazide; D014520:Urethane; C016767:sulprostone; D015237:Dinoprost; D000527:Alprostadil; C048491:butaprost; D015232:Dinoprostone; D009638:Norepinephrine