Anaphylactic death: the effect of aminoguanidine and heparin on histamine and stress hormones in guinea pigs.

The modifying effect of aminoguanidine (a histaminase inhibitor) and heparin (a histaminase liberator) on anaphylactic shock in guinea pigs was studied using ovalbumin as an antigen and trigger. The animals died of the shock, the time to death remaining unaltered by the drugs. Serum histamine and cortisol values were high after shock, but were reduced by heparin. Both noradrenaline and adrenaline in plasma were also elevated after shock, the final concentration of the latter being lowered by heparin. The lungs were dilated, indicating bronchoconstriction. The results confirm the role of histamine in anaphylactic shock and its potential value for the diagnosis in this kind of rapid death, in which morphological signs are scarce or lacking. Its diagnostic value still requires confirmation, however, which only autopsy studies can supply. It also appears that pretreatment of the animals with heparin affected the blood cortisol and catecholamines, which are involved in the shock mechanism as countermeasures, although aminoguanidine did not have any effect.