title: Aqueous humour flow after a single oral dose of isosorbide-5-mononitrate in healthy volunteers.
abstract: OBJECTIVE
  To investigate whether a nitric oxide donor given as a single oral dose is able to modify aqueous humour flow in healthy volunteers.
  
  
  METHODS
  Ten healthy volunteers participated in a randomized, double-masked and placebo-controlled cross-over study. Aqueous humour flow was assessed by fluorophotometry after intake of isosorbide-5-mononitrate (ISMN), 10 mg. Topical timolol maleate, which is known to reduce aqueous humour flow, was used as a positive control. Intraocular pressure (IOP) was measured by applanation tonometry and blood pressure was registered.
  
  
  RESULTS
  The basal rate of aqueous humour flow did not change significantly after a single oral dose of ISMN. The aqueous humour flow in the timolol-treated eye was reduced as compared to the contralateral control eye (p = 0.002). Mean IOP 6 hours after placebo and ISMN intake did not differ significantly. Timolol lowered IOP by 4 mmHg (p < 0.001). ISMN did not lower systolic blood pressure, but diastolic blood pressure was reduced by 4 mmHg (p = 0.048).
  
  
  CONCLUSIONS
  A single oral dose of 10 mg ISMN had no significant effect on aqueous humour flow in healthy volunteers.
authors.affiliation: Institute of Biomedicine, Pharmacology, Biomedicum Helsinki, University of Helsinki, Finland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Kotikoski
authors.forename: Olli
authors.initials: O
authors.lastname: Oksala
authors.forename: Heikki
authors.initials: H
authors.lastname: Vapaatalo
authors.forename: Esko
authors.initials: E
authors.lastname: Aine
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001082:Aqueous Humor / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D015590:Fluorophotometry; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects; D007548:Isosorbide Dinitrate / Q000008:administration & dosage* / Q000031:analogs & derivatives*; D008297:Male; D020030:Nitric Oxide Donors / Q000008:administration & dosage*; D013999:Timolol / Q000008:administration & dosage; D014065:Tonometry, Ocular
chemical_list: D020030:Nitric Oxide Donors; D013999:Timolol; D007548:Isosorbide Dinitrate; C030397:isosorbide-5-mononitrate