The Effect of Antiglaucoma Drugs on Rabbit Aqueous Humor Proteins Determined by Gel Electrophoresis

Previous studies indicate that there may be differences in the protein composition of the aqueous humor in normal and glaucomatous human eyes. These differences in protein composition and concentration may be due to the topical antiglaucoma medications used to treat glaucoma. These differences should be distinguished from any possible protein composition changes due to glaucoma. In order to study the effects of topical antiglaucoma medications on aqueous humor protein composition, we analyzed the aqueous humor of rabbit eyes topically treated with various antiglaucoma medications (timolol, pilocarpine, and dipivefrin). One eye of each rabbit was treated with the experimental drug, and the fellow eye was treated with saline solution (control). Thirty-six aqueous humor samples from 18 rabbits were obtained after 24 hours and 36 samples were obtained from 18 additional rabbits after 7 days of topical drug treatment. The protein composition of the aqueous humor samples was analyzed by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Significant protein differences in aqueous humor samples were found between the eyes treated with timolol and the control eyes, whereas no significant differences were found between the eyes treated with pilocarpine or dipivefrin and the controls. These protein differences ranged from 14,000 to 18,000 daltons in molecular weight.