Figure 9.

PGE₂ concentration (fmol 100 μl⁻¹) measured in cerebrospinal fluid collected by in vivo spinal dialysis of conscious rats before and after i.t. injection of NMDA (0.6 μg). Spinal dialysate is removed and assayed for PGE₂ by ELISA at baseline (b, average of two 20 min fractions collected prior to i.t. injection of NMDA) and F1: 0–20 min, F2: 20–40 min, and F3: 40–60 min after NMDA injection. Rats received (a and c) i.t. NMDA (0.6 μg) alone (black bars), and (a) i.t. AACOCF₃ (200 μg) or (c) i.t. BEL (30 μg) 20 min prior to i.t. NMDA (gray bars). In (b) and (d), the data are expressed as PGE₂ release (fmol 100 μl⁻¹) per minute during baseline (−40 to 0 min) and following NMDA injection (0–60 min) with or without pretreatment with PLA₂ inhibitor. I.t. injection of vehicle prior to i.t. NMDA or i.t. injection of vehicle alone did not affect PGE₂ release (data not shown). Each bar represents the average and s.e.m. for four to five rats per group and (^*) represents P<0.5 versus baseline.