CONCURRENT REDUCTION OF INFLAMMATION AND SPINAL FOS-LI NEURONS BY SYSTEMIC DICLOFENAC IN THE RAT

Intraplantar carrageenan induced a peripheral inflammation and c-Fos l ike immunoreactivity (Fos-LI) in the dorsal hem, IA-LS segments, of th e rat spinal cord. The total number of control carrageenan evoked Fos- LI neurons was 126 +/- 6 per section, which were predominately located in the superficial and deep laminae (41 +/- 2% and 39 +/- 2% of the t otal number of Fos-LI neurons per section) of the dorsal horn. Pre-adm inistered diclofenac (3, 6, 9 mg/kg i.v.) dose dependently reduced the number of Fos-LI neurons, with effects being strongest on the deep la minae Fos-LI neurons. The effects of diclofenac (9 mg/kg) on the numbe r of Fos-LI neurons (68 +/- 2% reduction) and inflamed ankle (72 +/- 7 % reduction) and paw (49 +/- 6% reduction) diameters, were positively correlated.