An immunohistochemical study of tryptase and chymase in the lungs of guinea pigs died of anaphylactic shock

Objective The aim of this study is attempted to provide an objective evidence for diagnosis of anaphylactic shock.Methods 24 healthy guinea pigs were randomly divided into experimental group and control group.For experimental group,animals were sub-grouped into animals of instantaneous death from anaphylactic shock,animals kept at 4℃ for 48h after death and those kept at-20℃ for 7d after death.For the control animals sub-groups were the same as the experimental animals.4 animals was in each sub-group.Anaphylacatic shock was induced in the experimental rabbits by intraventricular injection of human sera.Tryptase and chymase in the lungs were detected by immunohistochemical staining.Image analysis was performed.Results Tryptase-or chymase-positive mast cells were detected in the lungs in control animals,which were scattered around small vessels and bronchioles.Tryptase-positive or chymase-positive cells were significantly increased in number,and tryptase-or chymase-stained granules free from mast cells were detetced in the interstitial space in the lungs in the animals of deaths from anaphylactic shock.The preserving conditions did not affect the immunostaining for tryptase or chymase under 4℃ for 48h or-20℃ for 7d.Conclusion Immunostaining for tryptase and chymase may provide an objective method for diagnosis of anaphylactic shock.