FIG. 7.

Effect of trout liver S9 protein concentration on biotransformation of phenanthrene, pyrene, and benzo[a]pyrene. Data from substrate depletion studies are expressed in terms of fitted depletion rate constants (k_dep; panels A–C), calculated in vitro clearance rates (CL_{in vitro}; panels D–F), and unbound in vitro clearance rates (CL_{in vitro,u}; G–I). Reported k_dep estimates represent the mean ± SD of values determined in triplicate depletion assays. Free concentrations of each test chemical (panels J–L) were calculated using binding relationships shown in Figure 6.