Objective: To investigate the stimulation effect of 19 traditional Chinese medicine injections(TCMIs)on rat peritoneal mast cell degranulation in vitro. Method: The optimal reaction factors were found to detect histamine of release caused by TCMIs. And rat peritoneal mast cells were isolated and purificated as reference described. The cells were then incubated in Tyrode's containing 100 mL·L-1 TCMI or 4 mg·L-1 C48/80 for 1 h. After washing

degranulation was assessed by measuring histamine in cell lysates as previously described

and percentage of degranulated peritoneal mast cell were calculated in a modified method. Result: The optimal reaction time of histamine and O-phthaldialdehyde(OPT) to form a fluorophore is 3 min.The fluorophore is stability during 7.5-30 min after the reaction was terminated. Percentages of histamine release in two calculation methods showed no difference. The mast cells

stimulated by Tan-re-qing

Qing-kai-ling

Shen-mai

Dan-shen

Xue-sai-tong

Shen-fu Shuang-huang-lian

Sheng-mai

Xiang-dan

Re-du-ning

Fu-fang-dang-gui

had higher percentages in histamine release than that in control. But

those stimulated by Mai-luo-ning

Huang-qi

Ai-di

Xing-nao-jing

Huang-qi-duo-tang

Hong-hua

Yan-suan-chuang-xiong-qin

Shen-qi had no difference with the control in degranulation. Conclusion: Most hypersusceptibility caused by TCMIs may be anaphylactoid reactions. It suggests that rat peritoneal mast cell degranulation test by detecting histamine release can be used to evaluate anaphylactoid reactions caused by TCMIs.