Functional identification of AR subtypes in retinal microglial cells. TNF-α production was determined in LPS-treated (30 ng/ml, 12 hours) retinal microglial cells. A. In the presence of nonselective AR agonist NECA (1 μM) and subtype-selective AR antagonists for A1AR (CPX, 100 nM), A2AAR (ZM241385, 100 and 500nM), A2BAR (MRS 1754, 1 μM) and A3AR (MRS 1523, 10 μM). TNF-α levels were determined by ELISA (n=4 − 8). B. In the presence of varying concentrations of subtype-selective AR agonists: A1AR, CCPA, A2AAR, CGS 21680 and A3AR, IB-MECA.