The effects of betamethasone derivatives on endotoxin-induced uveitis in guinea pigs

Abstract.

Objective and Design: We reported previously that the betamethasone derivative betamethasone dipropionate behaves as an anti-glucocorticoid in rat endotoxin-induced uveitis (EIU). In the present study, we produced EIU in guinea pigs and investigated the effects of betamethasone dipropionate on the EIU.¶Material: Male Hartley guinea pigs were used.¶Treatment: Glucocorticoids were instilled into the eye.¶Method: To elicit EIU, lipopolysaccharide (LPS) was injected into the anterior chamber of the eye. Cell numbers in the aqueous humor after LPS injection were determined by flow cytometry. Prostaglandin E₂ (PGE₂) production after LPS injection into the anterior chamber was also examined.¶Results: Intracameral injection of LPS (1 μg/eye) induced cell infiltration into the anterior chamber and PGE₂ production. Betamethasone dipropionate inhibited cell infiltration and PGE₂ production more strongly than betamethasone. These results suggest that betamethasone dipropionate is a potent glucocorticoid in guinea pigs.¶Conclusions: Structure-activity relationships of glucocorticoids in the guinea pig EIU model may differ from those in the rat EIU model.