title: Contractile effect of aqueous Pleurotus tuberregium extract on the isolated bovine iris.
abstract: BACKGROUND
  Aqueous extract of Pleurotus tuberregium (PT) has been shown to reduce intraocular pressure (IOP) but the underlying mechanism has not been explained.
  
  
  OBJECTIVE
  To investigate the effect of PT on the bovine iris in vitro in comparison with acetylcholine (ACh).
  
  
  METHODS
  Strips of the iris were mounted in 10 ml organ baths and exposed to increasing concentrations of PT, ACh and a combination of both agents. The effect of atropine on the responses to the agents was also investigated.
  
  
  RESULTS
  PT and ACh separately caused contractile responses on the iris, but their effect reduced with higher concentrations. Combination of PT and ACh did not significantly alter the reduced responses seen with high concentrations of either agent. Atropine completely abolished the contractile responses of the agents.
  
  
  CONCLUSIONS
  The contractile effect of PT on muscarinic receptor-containing iris muscle may explain its IOP reducing property.
authors.affiliation: Department of Optometry, University of Benin, Benin City, Nigeria. gaakinlabi@yahoo.com
authors.forename: Ghalib A
authors.initials: GA
authors.lastname: Akinlabi
authors.forename: Osasere E
authors.initials: OE
authors.lastname: Asowata
authors.forename: Raymond I
authors.initials: RI
authors.lastname: Ozolua
authors.forename: Olukayode O
authors.initials: OO
authors.lastname: Akpaja
authors.forename: Vincent
authors.initials: V
authors.lastname: Iyawe
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D002417:Cattle; D004338:Drug Combinations; D005656:Fungal Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D007498:Iris / Q000502:physiology*; D009119:Muscle Contraction / Q000187:drug effects* / Q000502:physiology; D009130:Muscle, Smooth / Q000502:physiology*; D009184:Mydriatics / Q000494:pharmacology; D020076:Pleurotus / Q000737:chemistry*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D004338:Drug Combinations; D005656:Fungal Proteins; D009184:Mydriatics; D014665:Vasodilator Agents; D001285:Atropine; D000109:Acetylcholine