OBJECTIVE

The purpose of this study was to assess the efficacy of topically applied ketoprofen lysine salt (KLS), a cyclooxygenase inhibitor, against the inflammatory changes induced by interleukin-1beta (IL-1beta) and bradykinin (BK) in hamster cheek pouch microcirculation. In addition, we characterised the pharmacological regulation of IL-1beta activity in this model.

METHODS

Male Syrian hamsters were used. Microcirculation was visualised by fluorescent microscopy. Leukocyte adhesion, permeability, perfused capillary length (PCL) and capillary red blood cell (RBC) velocity were evaluated.

METHODS

KLS (25 microg/ml/min to 1.6 mg/ml/min) was topically applied for 3 min before topically administered IL-1beta (1microg/ml) and BK (10(-4) M). Monoclonal anti-mouse IL-1beta receptor antagonist (200 ng/ml), BK-B2 receptor antagonist (10(-6) M), PAF inhibitor (10(-5) M) and cycloheximide (10 microg/ml) were added topically 15, 10, 15 and 60 min, respectively, before IL-1beta (1 microg/ml).

RESULTS

IL-1beta caused a significant increase in microvascular permeability, a decrease in capillary RBC velocity followed by increased leukocyte adhesion in postcapillary venules. BK caused a marked increase in leukocyte adhesion and no decrease in PCL and RBC velocity. Treatment with KLS significantly inhibited both the leukocyte adhesion and microvascular leakage induced by the two mediators. The inflammatory effects induced by IL-1beta were reduced by blockade of IL-1beta receptors and by a BK-B2 receptor antagonist but were not affected by a PAF antagonist and protein synthesis inhibition.

CONCLUSIONS

These results demonstrate that KLS is effective in preventing early inflammatory changes induced by both IL-1beta and BK in the capillary network. Prostaglandin release and BK are essential components for IL-beta mediated responses, whereas neither PAF nor new protein synthesis appear to be linked to the early inflammatory changes induced by IL-1beta.