Effects of cyclic nucleotide analogs on intraocular pressure and trauma-induced inflammation in the rabbit eye

In this study the effects of cell-permeable 8-bromo-cAMP and 8-bromo-cGMP on intraocular pressure (IOP) and puncture-induced inflammatory response were investigated. Both 8-bromo-cAMP and 8-Bromo-cGMP reduced IOP when given subconjunctivally, but not topically. Subconjunctival administration of 8-bromo-cAMP induced a moderate disruption of the blood-aqueous barrier (BAB); in addition, subconjunctival 8-bromo-cAMP, but not topical 8-bromo-cAMP or subconjunctival 8-bromo-cGMP, reduced the disruption of the BAB and elevation of the aqueous PGE2 level after puncture trauma. It is concluded that the effects of 8-bromo-cAMP depend on the mode of administration, since this determines the concentration of 8-bromo-cAMP reached in the aqueous humor. It is suggested that 8-bromo-cAMP can partially suppress a slight inflammatory response by interference with the release of arachidonic acid from the tissues surrounding the aqueous humor.