Carbonic Anhydrase in the Cornea

Carbonic anhydrase activity in the corneas of adult man, human fetus, monkey, rabbit, rat, cow, pig and American bullfrog was examined by the histochemical method of Hansson. In all species the endothelial cells were intensely and distinctly stained for carbonic anhydrase activity. The enzyme inhibitor acetazolamide at 10‐‐5M in the incubation medium completely, and at 10‐‐6M almost completely, inhibited the staining. There was no staining in other parts of the cornea with the possible exception of a few cells in the frog epithelium. Endothelium, epithelium and stroma of cow and rabbit corneas were dissected and homogenized. The carbonic anhydrase activity was determined by a changing pH, indicator method. Only the endothelium showed activity and this was sensitive to inhibition by acetazolamide.