The effect of a novel, non-steroidal anti-inflammatory compound, nabumetone (BRL 14777), on cellular infiltration into 24-hour polyvinyl sponge implants in the rat, compared with some steroidal and non-steroidal anti-inflammatory drugs.

The time-course of cell migration into saline-soaked sponge implants over 5 days showed peak polymorphonuclear leucocyte (PMNL) infiltration at 24 h. In common with the corticosteroids dexamethasone and hydrocortisone, and the non-steroidal anti-inflammatory drugs indomethacin, (+)-naproxen, BW 755C and benoxaprofen, nabumetone decreased cell migration into the sponges. PMNLs and mononuclear cells were reduced at 24 h, and there was a parallel decrease in exudate levels of the lysosomal acid hydrolase beta-N-acetyl glucosaminidase [NAG ECB, 3, 2, 1, 30]. Impregnation of sponges with lambda-carrageenan (1%) caused a 2-3 fold increase in cell numbers, with a relatively greater proportion of PMNLs; drug effects were more marked in these implants.