Levels of cyclic-AMP, cyclic-GMP and betamethasone in the aqueous humor following topical administration of betamethasone in rabbit eyes.

The levels of cyclic-AMP, cyclic-GMP and betamethasone (BM) in the aqueous humor and serum BM following topical treatment with BM were determined using radioimmunoassay (RIA) methods. One drop of a solution containing 0. 1%, 0. 5% or 1. 0% BM was applied to the rabbit eye of 6 rabbits. The left eyes served as controls. BM was detected in the aqueous humor from right eyes 15 minutes after administration and peaked in 60-90 minutes. BM was also detected in the aqueous humor of the left eyes and in serum. Basal levels of cAMP and cGMP in the aqueous humor before BM treatment were 61. 5 and 4. 1 picomole/ml respectively, and changed little after BM treatment.