Carcinogenicity of dextran sulfate sodium in relation to its molecular weight.

The carcinogenicity of dextran and 3 kinds of dextran sulfate sodium with different molecular weights and almost the same sulfur content were compared in ACI rats. Dextran sulfate sodium of molecular weight 54,000 showed a strong carcinogenic activity when it was given orally as 2.5% diet, whereas dextran sulfate sodium of molecular weight 520,000 and 9500 and dextran showed no significant carcinogenicity, i.e. the peak of carcinogenic activity of dextran sulfate sodium appeared at molecular weight 54,000, and dextran sulfates with larger or smaller molecular weights had no carcinogenic activity.