IMPLANT EXUDATE LEUKOCYTE RESPONSE TO ANTIINFLAMMATORY DRUG-TREATMENT

Implantation of artificial materials elicits a local inflammatory resp onse. In this study a chamber model technique, allowing sampling of th e inflammatory exudate for further analysis in vitro, was used. Male S prague Dawley rats were injected daily with two different anti-inflamm atory drugs, betamethasone and indomethacin, and the local cellular re sponse was compared with a control group. The retrieved exudate was ev aluated with respect to the number of leucocytes, cell viability, diff erential counts and serum-opsonized zymosan stimulated chemiluminescen ce (CL). In all groups the majority of cells were polymorphonuclear gr anulocytes (PMNGs). Betamethasone and high-dose indomethacin (1.92 mg kg-1 body weight day-1) treatment caused a marked reduction in the num ber of accumulated leucocytes 6 days after implantation. A substantial inhibition of the CL response was observed 6 days after treatment wit h betamethasone (4.23 mg kg-1 body weight day-1). An increased CL resp onsiveness was observed after 24 h with low-dose indomethacin (0.03 mg kg-1 body weight day-1) and after 6 days with high-dose indomethacin (1.92 mg kg 1 body weight day-1) treatment. In summary, depending on t he anti-inflammatory drug treatment, dose and time after implant surge ry, either an inhibition or stimulation of leucocyte accumulation and activation was observed. This study shows the possibilities of samplin g the inflammatory exudate adjacent to a biomaterial implanted in vivo . This chamber model may be useful for the analysis of the inflammator y reaction around an implanted biomaterial during pharmacological trea tment.