A rat model of Shuang Huang Lian injection-induced anaphylaxis.

ShuangHuangLian Injection (SHLI) has induced many serious anaphylactic diseases, becoming a threat to the public health. However, study of the mechanism of the reaction and therapeutic approaches to it have been hindered by the lack of suitable animal models.We sought to develop a rat model that could mimic the characteristics of SHLI-induced anaphylaxis and the immunological changes that occur in clinical use.Brown Norway (BN) rats were sensitized twice at an interval of seven days with three doses of SHLI and challenged 14 days after the last administration. Different parameters, including the symptoms, the histamine levels and the pathological changes were analyzed. Antibody and cytokine levels were determined to explore the mechanisms involved.Total and SHLI-specific IgE levels were significantly increased after SHLI sensitization. Systemic symptoms, local skin reactions, elevated histamine levels and decreased blood pressures were observed after challenge. Histological examination revealed that slight pathological changes occurred in lungs while no obvious alteration was found in intestine. IL-4 but not IFN-gamma was significantly increased in spleen cells from SHLI-sensitized rats, indicating SHLI-induced anaphylaxis may be Th2-mediated.This rat model may provide a useful tool to study the mechanisms in SHLI-induced anaphylaxis and suggest some novel therapeutic approaches for this anaphylaxis.