The involvement of histamine, the cyclooxygenase system and the kallikrein-kinin system in acute inflammation generation, demonstrated with the Sephadex model in rats.

The involvement of histamine, the cyclooxygenase system and the kallikrein-kinin system in the generation of the Sephadex inflammation was investigated by in vivo-blocking of these systems. The changes of the inflammatory reaction after 12 h estimated by cellular migration and plasma exudation reflected the share of the investigated mediators. Blocking the cyclooxygenase by indomethacine caused a 59.1% reduction of the neutrophil and a 77.6% reduction of the lymphocyte reaction. Blocking the kallikrein-kinin system also had inhibitory effects, whereby the way of action probably works via the cyclooxygenase system. Blocking histamine had, in essence, no effect on cellular migration. In all variations of the experiment, the exudation of plasma components was only slightly reduced. There are indications that the flux of mediator activation can bypass a blocked site.