Toxicology of Industrial Compounds

Figure 19.9 Hepatic events leading to hormone elimination.
C.K.ATTERWILL AND S.P.AYLWARD 271
phenobarbital is able to increase the thyroxine clearance in a relatively
short timespan (Atterwill, unpublished observations). New in vitro data are
not inconsistent with the time course of the in vivo phenomena where
enhanced T 4 hepatocytic accumulation by cultured rat hepatocytes
following compound exposure occurred as early as 60–90 min after
exposure (Aylward et al., 1994). There was no membrane cytotoxic effect
of the compounds at the threshold concentrations producing these effects in
vitro. This shows a potential rapid direct effect of the xenobiotics on