Fig. 7.

Effects of acute hepatic heme depletion and repletion on PB-mediated CYP2B induction in cultured MGB wild-type [WT; HRI (+/+)] and HRI knockout [KO; HRI (−/−)] mouse hepatocytes. WT or KO mouse hepatocyte cultures were untreated or heme (H)-depleted (first two lanes), or pretreated with PB (next four lanes): alone (lane 3), with heme (H-control; lane 4), heme depletion (H-depleted; lane 5), or heme repletion after heme depletion (H-repleted; lane 6), as detailed under Materials and Methods. A representative example of CYP2B Western immunoblotting analyses of these hepatocyte lysates (30 μg of protein) is shown at the top, with corresponding aliquots used for actin immunoblotting analyses as loading controls. Densitometric quantification of hepatic CYP2B content from three individual experiments is shown at the bottom. Statistical analyses revealed significant differences in hepatic CYP2B content between the two mean ± S.D. values each marked with the same symbol as follows: *, p < 0.001; §, p < 0.001; ‡, p < 0.001; ¶, p < 0.001; €, p < 0.001; #, p < 0.001; =, p < 0.001; and **, p < 0.001. No statistically significant differences were observed between PB-pretreated/H-control and PB/H-repleted WT lysates.