Figure 1.
Hepatocyte proliferation after PCN and/or TCPOBOP treatment in mice.
Male mice were treated intraperitoneally with vehicle (corn oil; Control), TCPOBOP (TC; 3 mg/kg), PCN (100 mg/kg) or both for 48 h. (A) The liver to body weight ratios were calculated. (B) Livers were fixed and stained with anti-Ki-67 antibody for the proliferating cell nuclei. Arrowheads indicate Ki-67-positive nucleus. (C) The percentage of Ki-67-positive nuclei was calculated as described in Materials and Methods. (D) Total hepatic RNAs were subjected to quantitative RT-PCR for Cyp2b10, Cyp3a11 and Ccnb1. Values are the mean ± SD (n = 3 or 4). Columns not sharing a common letter (a, b and c) differ significantly with each other (P<0.05; Tukey-Kramer test).
Figure 2.
Influences of PCN co-treatment on the hepatocyte proliferation induced by TCPOBOP treatment in PXR-deficient mice.
Male Pxr−/− mice were treated intraperitoneally with vehicle (corn oil; Control), TCPOBOP (TC; 3 mg/kg), PCN (100 mg/kg) or both for 48 h. (A) The liver to body weight ratios were calculated. (B) Livers were fixed and stained with anti-Ki-67 antibody. Arrowheads indicate Ki-67-positive nucleus. (C) The percentage of Ki-67-positive nuclei was calculated as described in Materials and Methods. (D) Total RNAs extracted from the liver were subjected to quantitative RT-PCR for Cyp2b10 and Ccnb1. Values are the mean ± SD (n = 4). Columns not sharing a common letter (a and b) differ significantly with each other (P<0.05; Tukey-Kramer test).
Figure 3.
Influences of 1-week feeding with PCN and/or PB on the hepatocyte proliferation.
Male mice were fed a normal diet (Control) or a diet containing PB (1000 ppm), PCN (500 ppm) or both for 1 week. (A) The liver to body weight ratios were calculated. (B) Livers were fixed and stained with anti-Ki-67 antibody. Arrowheads indicate Ki-67-positive nucleus. (C) The percentage of Ki-67-positive nuclei was calculated as described in Materials and Methods. (D) Total RNAs extracted from the liver were subjected to quantitative RT-PCR for Cyp2b10, Cyp3a11, Mcm2, Ccna2 and Ccnb1. Values are the mean ± SD (n = 4). Columns not sharing a common letter (a, b, c and d) differ significantly with each other (P<0.05; Tukey-Kramer test).
Figure 4.
Influences of PCN co-treatment on the hepatocyte proliferation induced by single Wy-14643 treatment.
Male mice were treated intraperitoneally with vehicle (corn oil; Control) or Wy-14643 (Wy; 150 mg/kg) in combination with or without PCN (100 mg/kg) for 48 h. (A) The liver to body weight ratios were calculated. (B) Livers were fixed and stained with anti-Ki-67 antibody. Arrowheads indicate Ki-67-positive nucleus. (C) The percentage of Ki-67-positive nuclei was calculated as described in Materials and Methods. (D) Cyp4a10, Mcm2, Ccna2 and Ccnb1 mRNA levels were determined by quantitative RT-PCR. Values are the mean ± SD (n = 3 or 4). Columns not sharing a common letter (a, b and c) differ significantly with each other (P<0.05; Tukey-Kramer test).
Figure 5.
Influence of PCN treatment on the G0/G1 transition of mouse hepatocytes.
(A, B) Male mice were treated intraperitoneally with vehicle (corn oil; Control), PCN (100 mg/kg) or TCPOBOP (3 mg/kg) and primary hepatocytes were isolated by collagenase perfusion method from the liver 48 h after treatment. Fixed cells were incubated with PI for DNA staining to determine cell cycle distribution (A) or with 7-AAD and Pyronin Y for DNA and RNA staining, respectively, to separate G0 and G1 phase cells (B) by flow cytometry. P1 and P2 fractions represent G0/G1-phase 4 n hepatocytes and G2/M-phase 4 n or G0/G1-phase 8 n hepatocytes, respectively. One set of representative results among 4 independent experiments is shown. (C) Male mice were treated intraperitoneally with vehicle (corn oil; Control), TCPOBOP (TC; 3 mg/kg) and/or PCN (100 mg/kg) for 24 h. Total RNAs extracted from the liver were subjected to quantitative RT-PCR for the indicated genes. Columns not sharing a common letter (a, b and c) differ significantly with each other (P<0.05; Tukey-Kramer test).