Interrelations of the Blood-Aqueous Potential and Acetazolamide in the Rabbit

¹ Department of Ophthalmology and the Oscar Johnson Institute, Washington University School of Medicine, St. Louis, Mo.

The intravenous administration of 100 mg. per kilogram of acetazolamide produced a 0.9 mv. abrupt fall in the 7 mv. resting potential, and was followed by a 1.4 mv. rise that persisted for more than 20 minutes. This alteration was not influenced by the previous injection (50 minutes) of 100 µg per kilogram of strophanthin K or nephrectomy (18 hours). One hundred milligrams per kilogram of ammonium chloride produced a 3.7 mv. rise in 37 seconds that lasted 25 minutes. If this injection was followed by acetazolamide in 2 minutes, the changes from the carbonic anhydrase inhibition could be noted, but the rise in positivity was prolonged for 37 minutes. The administration of 225 mg. per kilogram of 0.6M sodium bicarbonate lowered the gradient 1.5 mv. with a return to base line at IS minutes. An infusion of 535 mg. per kilogram for 90 minutes, however, did not alter the gradient or the response to acetazolamide in spite of the plasma bicarbonate being elevated to 29 mg. per cent. Sodium fluoroacetate (0.25 mg. per kilogram) reduced the potential 1.8 mv., and the increase of positivity due to acetazolamide was maintained for the duration of the experiment in 5 of the 6 rabbits.