In vivo AND in vitro EFFECTS OF ENDOTOXIN ON PROSTAGLANDIN RELEASE FROM RAT LUNG

Abstract

1 The release of prostaglandins (PGE₂, PGF_2α, PGI₂) and thromboxane A₂ (T×A₂) from rat lung exposed to E. coli endotoxin, in vivo ox in vitro has been studied. 2 Lung strips of endotoxin-treated rats demonstrated a preferential increase of T×A₂ and PGF_2α and a decrease in the ratio PGI₂/T×A₂. 3 These data suggest that changes in the proportions of arachidonic acid metabolites might play a role in the pulmonary pathophysiology during endotoxin shock. 4 Incubation of lung strips with endotoxin in vitro failed to stimulate prostaglandin release; paradoxically, it suppressed both the spontaneous and the ionophore-induced prostaglandin release. 5 These findings suggest that the increase in prostaglandin release by the lung following endotoxin administration in vivo is probably mediated by factor(s) generated in endotoxaemia and is not due to a direct action of endotoxin on the lung tissue.