Effects of adrenergic drugs on aqueous cAMP and cGMP and intraocular pressure.

The following variously selective adrenergic agonists were tested for their effects on the concentration of adenosine 3',5' cyclic monophosphate and guanosine 3',5- cyclic monophosphate in the aqueous humor of treated and fellow eyes of rabbits one hour after topical unilateral application (2 mg, base): Epinephrine (alpha, beta 1.beta 2), phenylephrine alpha), isoproterenol (beta 1, beta 2), tazolol (beta 1) and terbutaline (beta 2). All drugs produced a significant increase in cAMP in the treated eyes and all but terbutaline produced a significant increase in the fellow eye. Terbutaline alone caused an increased in cGMP although a similar dose of pilocarpine, a cholinergic agonist, was ineffective in changing cGMP levels. We conclude that (1) diverse adrenoceptor stimulation can increase cAMP, but (2) not necessarily in direct relation to an agent's hypotension induced by pilocarpine is not accompanied by an increase in aqueous cGMP.