Leukotriene B 4, interleukin 1 and leucocyte accumulation in titanium and PTFE chambers after implantation in the rat abdominal wall

Abstract

The inflammatory reaction elicited after implantation of non-biologic materials was studied by analysis of the exudate in pure titanium or polytetrafluorethylene chambers 1–9 d after insertion in the abdominal wall of the rat. In chambers made of pure titanium, the number of leucocytes increased about twofold from 1.8 × 10 6/ ml to 4.1 × 10 6/ ml between 24 h and 6 d, whereas a larger increase from 2.1 × 10 6/ ml to 8.3 × 10 6/ ml was observed in the polytetrafluorethylene chambers. Irrespective of implant material, polymorphonuclear granulocytes constituted the vast majority of leucocytes (>81%). After 24 h the leukotriene B 4 content was slightly higher in polytetrafluorethylene chambers than in titanium chambers. In contrast to the titanium chambers, a marked increase in leukotriene B 4 levels was detected in polytetrafluorethylene chambers 6 d after insertion, whereas the greatest amount of leukotriene B 4 in titanium chambers was measured at 9 d. Interleukin 1 was only detected in both types of chambers after 6 d. The present study, together with previous findings, shows that the materials used in this study elicit different degrees of inflammatory reactions in the chamber exudate. Since the number of leucocytes in the exudate retrieved from the chambers correlated well with the leukotriene B 4 levels, it is suggested that leukotriene B 4, but not interleukin 1, may be an important mediator for polymorphonuclear granulocyte migration into the implant-tissue interface. The role of leukotriene B 4 and interleukin 1 for other parts of the inflammatory process around biomaterials in soft tissue, such as cell adhesion and activation and microvascular changes and their potential roles for the development of the peri-implant tissue remains to be established.