POTENTIATION OF THE MYDRIATIC EFFECT OF NOREPINEPHRINE IN THE RABBIT AFTER MONO-AMINE OXIDASE INHIBITION

  • 1 January 1979
    • journal article
    • research article
    • Vol. 18  (2) , 200-203
Abstract
Dose-response curves of pupillary dilation after topical administration of norepinephrine or methoxamine were determined in rabbits after chronic inhibition of ocular monamine oxidase [EC 1.4.3.4] by treatment with pargyline or pheniprazine. Eyes treated with either monoamine oxidase inhibitor showed an enhanced responsiveness to the mydriatic effect of norepinephrine given either topically or i.v. Increments in pupil size of the treated and control eyes in response to methoxamine applied topically were the same. These results suggest that monoamine oxidase may play a role in the iris as one factor influencing the norepinephrine concentration at the receptors.