title: Effect of topical nipradilol on retinal microvascular leukocyte adhesion in diabetic rats.
abstract: BACKGROUND
  Retinal leukostasis plays an important role in the pathogenesis of diabetic retinopathy.
  
  
  OBJECTIVE
  We studied the effects of nipradilol, a topical antiglaucoma alphabeta-blocker and nitric oxide donor, on the retinal vascular leukocyte adhesion of rats with diabetes.
  
  
  METHODS
  Diabetes was induced in seven Brown-Norway rats by one intravenous injection (65 mg/kg) of streptozotocin and confirmed by blood glucose levels >350 mg/dl 48 h after the injection. Nipradilol solution was instilled in the right eye and nipradilol-free base solution in the left eye for 3 weeks, after which the retinal microcirculation was evaluated by acridine orange leukocyte digital fluorography using laser scanning ophthalmoscopy. Leukocytes trapped in the retina were counted around the optic disc in a 5-disc-diameter area and compared between the right and the left eye.
  
  
  RESULTS
  The mean retinal leukostasis count in the nipradilol-treated eyes (19 +/- 15 cells) was significantly lower than in the untreated eyes (49 +/- 19 cells; p < 0.0008). The diameter of the retinal artery in the eyes treated with nipradilol significantly increased (111 +/- 13.5%) compared with untreated eyes (p < 0.03).
  
  
  CONCLUSIONS
  Topical nipradilol significantly reduced retinal leukostasis in the retinal microcirculation in diabetic rats and may be a prophylactic agent for early diabetic retinopathy through its nitric oxide donor effects on the microcirculation.
authors.affiliation: Department of Ophthalmology, Omiya Medical Center, Jichi Medical University, Saitama, Japan.
authors.forename: Ryuichiro
authors.initials: R
authors.lastname: Ono
authors.forename: Akihiro
authors.initials: A
authors.lastname: Kakehashi
authors.forename: Yuka
authors.initials: Y
authors.lastname: Ito
authors.forename: Norito
authors.initials: N
authors.lastname: Sugi
authors.forename: Shinji
authors.initials: S
authors.lastname: Makino
authors.forename: Eiji
authors.initials: E
authors.lastname: Kobayashi
authors.forename: Yoji
authors.initials: Y
authors.lastname: Hakamada
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Takagi
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kitazume
authors.forename: Masanobu
authors.initials: M
authors.lastname: Kawakami
mesh_terms: D000287:Administration, Topical; D000317:Adrenergic alpha-Antagonists / Q000008:administration & dosage* / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000008:administration & dosage* / Q000494:pharmacology; D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects*; D003921:Diabetes Mellitus, Experimental / Q000503:physiopathology; D003930:Diabetic Retinopathy / Q000503:physiopathology*; D005451:Fluorescein Angiography; D007958:Leukocyte Count; D007962:Leukocytes / Q000502:physiology*; D018921:Leukostasis / Q000188:drug therapy / Q000503:physiopathology; D008833:Microcirculation; D009569:Nitric Oxide / Q000378:metabolism; D020030:Nitric Oxide Donors / Q000008:administration & dosage / Q000494:pharmacology; D009883:Ophthalmic Solutions / Q000008:administration & dosage / Q000494:pharmacology; D011412:Propanolamines / Q000008:administration & dosage* / Q000494:pharmacology; D051381:Rats; D011914:Rats, Inbred BN; D012161:Retinal Artery / Q000502:physiology*
chemical_list: D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists; D020030:Nitric Oxide Donors; D009883:Ophthalmic Solutions; D011412:Propanolamines; D009569:Nitric Oxide; C036089:nipradilol