Formation of prostanoids during intravascular complement activation in the rabbit

Abstract

Plasma concentrations of 6‐oxo‐prostaglandin F1α (6‐oxo‐PGF1α) and thromboxane B2 (TXB2) were measured by radioimmunoassay in arterial blood before and after injections of the complement activator, cobra venom factor (CVF). During the control period, the concentration of 6‐oxo‐PGF1α, which gives the sum of prostacyclin plus 6‐oxo‐PGF1α, and TXB2 were, respectively, less than 20 pg ml−1 and 70 ± 15 pg ml−1. Intravenous injections of CVF induced dose‐dependent, reversible elevations in the plasma levels of both prostanoids. The time courses for the increases of 6‐oxo‐PGF1α and TXB2 paralleled the arterial hypotension and thrombocytopenia, suggesting the existence of a causal relationship between these parameters. The results further support our hypothesis that complement‐dependent formation of arachidonic acid metabolites contributes to some of the haemodynamic and haematological changes occurring during endotoxin shock. 1985 British Pharmacological Society