Fig. 8.

Metabolism of [³H]MC and its metabolites by radiometric TLC (A) in HepG2 cells (B) and media (C). A, HepG2 cells were treated with [³H]MC (2.5 μM; 1.9 Ci/mmol), and at different time points (6–96 h), the cells were harvested, extensively washed, and then MC and its metabolites were extracted with chloroform/methanol. The total radioactivity, representing MC and its metabolites, was measured, and the material was then subjected to radiometric TLC. B, the parent MC and metabolite zones were then excised from TLC plates, counted, and intracellular levels of MC and its metabolites were estimated. Values represent mean ± S.E. of at least three independent treatments of the cells. C, HepG2 cells were treated with [³H]MC, as described in legend to B, and at the indicated time points, the media were extracted with chloroform/methanol, and MC and its metabolites were quantified by radiometric TLC, as described under Materials and Methods. Values represent mean ± S.E. of at least three independent treatments of the cells.