Antimuscarinic action of oxymetazoline on human intraocular muscles.
At 10 microM or 100 microM concentration of oxymetazoline, the activity of carbachol was competitively blocked on the isolated human iris sphincter or ciliary muscles. On the ciliary muscle, the dissociation constant K(B) of 5.2 microM was obtained. The value is approximately equal to that on the iris sphincter. Even though it is a weakly active antimuscarinic drug with potent alpha-adrenoceptor-mediated vasoconstriction activity, the therapeutic benefit in ocular decongestion recovery may be partly related to the weak anticholinergic activity.
Division of Pharmacology, College of Pharmacy, Ohio State University, Columbus, OH., USA.
Popat N
PN
Patil
Hitoshi
H
Ishikawa
D004305:Dose-Response Relationship, Drug; D006801:Humans; D066298:In Vitro Techniques; D018727:Muscarinic Antagonists / Q000494:pharmacology*; D009801:Oculomotor Muscles / Q000187:drug effects* / Q000502:physiology; D010109:Oxymetazoline / Q000494:pharmacology*
D018727:Muscarinic Antagonists; D010109:Oxymetazoline