Fig. 2.

Preincubation with MK-801 blocks NMDA NR1 upregulation in synoviocytes. A: low-power photomicrograph of glutamate NMDA NR1 receptors (red) stained with rabbit anti-NMDA NR1 antibody on control untreated synovial cells. B: cells incubated concurrently with 5 μM NMDA and 5 μM ACPD for 6 h. C: cells preincubated for 1 h with 10 μM MK-801, a selective, noncompetitive NMDA receptor antagonist, and then incubated for 6 h with 5 μM NMDA and 5 μM ACPD. Dual nuclear counterstaining with DAPI is shown in blue. Bar, 80 μm.