Absence of drug effects on rabbit blood-aqueous barrier permeability to non-electrolytes

The effects of either topical epinephrine, norepinephrine or pilocarpine upon the entry of non-transported radioactive solutes into the anterior or posterior chamber of pigmented rabbit eyes was examined after intravenous solute perfusion. Solutes employed were urea, thiourea, sucrose and inulin. They were infused at a rate that maintained constant plasma levels from 1 minute through 5 hours of intravenous perfusion. Anterior and posterior chamber samples were taken at either 5 minutes or 5 hours after infusion of solutes, but in either case at 1 hour after drug administration. Differences between the 5 minute and 5 hour data showed more solute entry with the passage of time, and differences were found between the rate of solute entry at both times based upon molecular size. However, while occasional statistically significant differences were found between certain drug treatments, no drug effects were noted on solute entry into the treated eye either when compared to the contralateral untreated eye or to a separate untreated control group.