<prompt> Agonistic action at which of the following adrenergic receptors results in the reduction of aqueous secretion?b1 receptorb2 receptorM2 receptora2 receptor  <response>: Stimulation of a2 receptors located on ciliary epithelium reduces secretion of aqueous humor. They are useful in glaucoma as they reduce the i.o.t a2 agonists used in glaucoma are : Apraclonidine and Brominidine 