title: The effects of naloxone on retinal ischemia in rats.
abstract: The efficacy of naloxone (NL), a broad spectrum opioid antagonist, on retinal ischemia, was evaluated in a rat model of retinal ischemia with histopathologic and morphometric criteria. Two intraperitoneal injections of naloxone 3 mg/kg given immediately and 6 hr after reperfusion showed beneficial effects to the retina as evaluated at 2, 7, and 14 days after reperfusion. Morphologically, the naloxone-treated group showed better-preserved ganglion cells, nerve fiber layer, and inner nuclear layer. Morphometrically, in the treated groups, inner retinal thickness at all three time points and ganglion cell counts at 7 days showed higher values than vehicle controls. This beneficial effect of naloxone was dose-dependent with a minimal effective total dose of 6 mg/kg. A possible role of opiate receptors in retinal ischemia is suggested.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago.
authors.forename: T T
authors.initials: TT
authors.lastname: Lam
authors.forename: K
authors.initials: K
authors.lastname: Takahashi
authors.forename: M O
authors.initials: MO
authors.lastname: Tso
mesh_terms: D000818:Animals; D002452:Cell Count; D004305:Dose-Response Relationship, Drug; D007274:Injections, Intraperitoneal; D007511:Ischemia / Q000188:drug therapy* / Q000473:pathology; D008297:Male; D009270:Naloxone / Q000494:pharmacology / Q000627:therapeutic use*; D009412:Nerve Fibers / Q000187:drug effects / Q000473:pathology; D009474:Neurons / Q000187:drug effects / Q000648:ultrastructure; D051381:Rats; D011917:Rats, Inbred Lew; D012165:Retinal Ganglion Cells / Q000187:drug effects / Q000648:ultrastructure; D012171:Retinal Vessels
chemical_list: D009270:Naloxone