Dose-dependent influence of topically instilled adrenergic agents on intraocular pressure and outflow facility in the rabbit

• Published in: Experimental eye research Vol. 12; no. 1; pp. 80 - 87
• Main Author: Lorenzetti, O.J.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.07.1971
• Subjects: Animals; Anterior Chamber; Aqueous Humor - drug effects; Blood Pressure - drug effects; Epinephrine - administration & dosage; Epinephrine - pharmacology; Heart Rate - drug effects; Intraocular Pressure - drug effects; Isoproterenol - administration & dosage; Isoproterenol - pharmacology; Methylcellulose - pharmacology; Phenylephrine - administration & dosage; Phenylephrine - pharmacology; Rabbits; Receptors, Drug; Tears - drug effects
• ISSN: 0014-4835; 1096-0007
• DOI: 10.1016/0014-4835(71)90131-X

Epinephrine, phenylephrine and isoproterenol were evaluated by topical instillation in the rabbit eye and found to produce dose-dependent lowering of the elevated intraocular pressure. This response for epinephrine was biphasic, producing a slope at lower concentrations (0·01–0·1%), which was independent of outflow facility effects. At higher (1–10%) concentrations the intraocular pressure response with epinephrine was dependent on outflow facility. Phenylephrine was approximately one-fifth as active as epinephrine in lowering intraocular pressure and had equivalent effects on outflow facility. Isoproterenol was twice as potent as epinephrine in lowering intraocular pressure but had only one-tenth the effect on outflow facility. The results suggest different receptor mechanisms in controlling intraocular pressure effects exclusive of outflow facility influence.