Endogenous leukotriene D4 formation during anaphylactic shock in the guinea pig

Experiments on the metabolism and excretion of i.v. administered selectively labeled [3H8]leukotriene C4 in bile duct-cannulated guinea pigs indicated predominantly biliary excretion of tritium. The major leukotriene metabolite in bile was identified as leukotriene D4. By monitoring leukotriene excretion radioimmunochromatographically, it was shown that guinea pigs suffering from anaphylactic shock produce leukotriene D4 endogenously. Immunological challenge of animals sensitized to ovalbumin was accompanied by an increase of biliary leukotriene D4 concentrations from 10 +/- 1 to 86 +/- 10 nM (mean +/- SEM, n = 5, P less than 0.001). When considering that bile flow was decreased to about half after challenge, the excretion rate of leukotriene D4 in bile increased from 0.88 +/- 0.16 before to 3.18 +/- 0.38 pmol X min-1 X kg-1 after challenge (mean +/- SEM, n = 5, P less than 0.002). It is concluded that systemic anaphylaxis in the guinea pig is associated with endogenous generation of leukotriene C4 (up to 1 nmol/kg during a 30-min period after the challenge.