The linear relationship between the deviation of observed combined toxicity of two agents from the toxicity of sham interaction and the product of their doses

研究发现，与假联合作用毒性相比两因素联合所致毒性改变（无论增强或减弱）与其剂量积之间呈线性关系．假联合作用的建立是基于这样的假设，即在联合作用中因素Ｂ的作用与等效剂量的因素Ａ的作用相同，反之亦然．本研究显示的不同的两因素联合作用中该线性关系的一致性以及大多数报道的等效线图提示，该线性关系可能对两因素联合作用具有广泛的适用性．然而，该线性关系的确切适用范围仍有待于更多实验数据检验确定．该线性关系不仅可用于两因素联合作用的定性评价，而且可用于两因素联合作用剂量－反应关系的建立．

The linear relationship between the deviation of observed combined toxicity of two agents from the toxicity of sham interaction and the product of their doses

The discovery of linear relationship between the deviation (either positive or negative) of the observed combined toxicity from the toxicity of sham interaction and the product of doses of these two agents has been described in the present study. The sham interaction was constructed with the assumption that any dose of B acted as its corresponding equieffective dose of A, or vice versa. The very consistent linear relationship demonstrated in different combinations of two agents in the present study and the most of reported isobolograms suggest that the linear relationship be applicable to the most of interaction between two agents. But the exact scope of the application of the discovered relationship still need further examination with more experimental data. The linear relationship could be used as general approach not only to qualitative evaluation of combined effects of two agents but also to construction of dose response curve for combination of two agents.