title: Elevation of atrial natriuretic peptide levels in aqueous humor of the rabbit by kappa opioid receptor agonists.
abstract: Following the topical administration of three kappa agonists (bremazocine, spiradoline and ICI 204448) to rabbit eyes, aqueous humor samples were analyzed for levels of atrial natriuretic peptide (ANP). Bremazocine (BRE) and spiradoline (SPR) elevated aqueous ANP levels in a dose-dependent manner. In contrast, ICI had no significant effect on ANP levels in aqueous humor. Nor-binaltorphimine (nor-BNI), a selective kappa opioid receptor antagonist, was used to assess kappa opioid receptor involvement and glibenclamide, an ATP-sensitive K+ channel blocker, was used to test for the role of ATP-sensitive potassium channels in ANP release. Pretreatment with nor-BNI antagonized the increases in ANP levels observed with both BRE and SPR. Likewise, glibenclamide suppressed the stimulation of ANP secretion by bremazocine. In summary, BRE and SPR increased ANP levels in aqueous humor of rabbits, in part, via activation of K+(ATP) channels that are assumed to be associated with kappa opioid receptors.
authors.affiliation: Morehouse School of Medicine, Department of Pharmacology and Toxicology, Atlanta, GA 30310-1495, USA. russelk@msm.edu
authors.forename: K R
authors.initials: KR
authors.lastname: Russell
authors.forename: T T
authors.initials: TT
authors.lastname: Moore
authors.forename: D E
authors.initials: DE
authors.lastname: Potter
mesh_terms: D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000494:pharmacology; D001082:Aqueous Humor / Q000737:chemistry*; D009320:Atrial Natriuretic Factor / Q000378:metabolism*; D001575:Benzomorphans / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005123:Eye / Q000187:drug effects*; D005905:Glyburide / Q000494:pharmacology; D008297:Male; D009271:Naltrexone / Q000031:analogs & derivatives* / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D011759:Pyrrolidines / Q000494:pharmacology*; D011817:Rabbits; D011863:Radioimmunoassay; D017473:Receptors, Opioid, kappa / Q000819:agonists*
chemical_list: D000700:Analgesics; D000889:Anti-Arrhythmia Agents; D001575:Benzomorphans; D009292:Narcotic Antagonists; D011759:Pyrrolidines; D017473:Receptors, Opioid, kappa; C060223:ICI 204448; C051844:norbinaltorphimine; D009271:Naltrexone; D009320:Atrial Natriuretic Factor; C027248:bremazocine; C051272:spiradoline; D005905:Glyburide