Permeability of the fish intestinal membrane to bulky chemicals

The ability to predict the environmental behavior of chemicals precisely is important for realizing more rational regulation. In this study, the bioaccumulation of nine chemicals of different molecular weights absorbed via the intestinal tract was evaluated in fish using the everted gut sac method. The amounts of chemicals that passed through the intestinal membrane after a 24-hr exposure were significantly decreased for chemicals with MW >= 548 and D-max (min)>= 15.8 A (or D-max aver >= 17.2 A). These thresholds are consistent with those previously proposed in terms of MW (>800) and molecular size (D(max min>)15.6 angstrom or D-max aver>17.1 angstrom) for the limit of permeable chemicals through the gill membrane. The results show that the same MW and D-max criteria can be used to predict low bioaccumulation through both the gill membrane and the intestinal tract. These findings are helpful in reducing the need to conduct animal tests in environmental safety studies.

Automated summary

The ability to predict the environmental behavior of chemicals is crucial for better regulation. This study evaluated the bioaccumulation of different chemicals in fish using a specific method, and found that the same criteria could be used to predict low bioaccumulation through both the gill membrane and the intestinal tract.