PAF-acether and leukotriene participation in acute circulatory shock.

The fact that PAF-acether elicites acute circulatory collapse in anesthetized dogs supports the hypothesis that its endogenous double is involved in shock state events. The fact that cysteinyl containing leukotrienes has been shown to be released in various shock states, themselves producing noxious effects related to such circulatory disturbances, suggests a possible role of these arachidonic acid metabolites in shock syndrome. The present report summarizes the part played by these mediators in shock developments.

Dependency of the Paf-acether induced bronchospasm on the lipoxygenase pathway in the guinea-pig.

The Paf-acether (platelet-activating factor) induced bronchospasm (Paf-BCS) was studied in the anesthetized guinea-pig. The SRS antagonist, FPL-55712, as well as inhibitors of both lipoxygenase and cyclooxygenase, phenidone, nordihydroguaiaretic acid (NDGA), and benoxaprofen, caused a dose-related antagonism of Paf-BCS. By contrast, selective inhibitors of cyclooxygenase, indomethacin and aspirin, exerted moderate antagonism at intermediate doses, but had no effect at high doses.

Acute circulatory collapse caused by platelet-activating factor (PAF-acether) in dogs.

Synthetic platelet-activating factor (PAF-acether) was shown to act as a shock inducer when a dose of 9 or 36 nmol . kg-1 was injected i.v.

Platelet-activating factor acether (PAF-acether) involvement in acute inflammatory and pain processes.

PAF-acether is a potent aggregating agent released by various cells involved in acute inflammatory process. In this paper, exogenous PAF-acether has been investigated for its ability to generate signs of inflammation (edema measured by plethysmometry) and hyperalgesia (Randall-Sellito test) by standard subplantar injection in the rat paw. From 0.