Phthalate ester metabolism in the isolated, perfused rat liver system.

A series of experiments, performed at Johns Hopkins University, which led to our finding that plasticizers are extracted from poly-(vinyl chloride) (PVC) plastic by blood and biologic fluids will be described. The experiments began with the appearance of an unknown compound in the isolated perfused liver system. Livers were perfused with a mixture of synthetic plasma containing bovine serum albumin and rat blood. At the end of the perfusion the livers were homogenized, a perchloric acid extract made, and column chromatography performed. In one such experiment, in addition to the expected adenine nucleotides, an additional peak was observed which eluted from the column between ADP and ATP. The unidentified material absorbed ultraviolet light at 260 nm. A comparable peak was not observed when samples of liver were assayed prior to perfusion. In addition to this finding of an unidentified material in the perfused liver, we also observed accumulation of this material in the perfusate. This result is shown in Figure 1. In this figure the broken lines indicate the acid-soluble extract obtained from perfusion fluid that was not circulated through an intact liver; the solid lines indicate the compounds that appear in the presence of