The effect of acetazolamide on the movements of anions into the posterior chamber of the dog eye.

The rate of entry of bicarbonate and chloride ions the posterior chamber of the dog, a species that has both HCO3- and Cl- concentrations in excess of plasma in this chamber, was measured in order to clarify the mechanisms involved in the produciton of aqueous humor. Four animals were given H14CO3- and 36Cl- intravenously first in a control series and then after pretreatment with acetazolamide, (50 mg/kg), a carbonci anhydrase inhibitor. Samples were taken from arterial blood and the posterior chamber. Acetazolamide did not affect chloride entry into the posterior chamber but bicarbonate entry was decreased about 50%. It is concluded that in this species, bicarbonate is the key anion for the decrease of aqueous humor production caused by the administration of acetazolamide.