Hepatic regeneration after sublethal partial liver irradiation in cirrhotic rats.

Our previous animal study had demonstrated that partial liver irradiation (IR) could stimulate regeneration in the protected liver, which supported the measurements adopted in radiotherapy planning for hepatocellular carcinoma. The purpose of this present study is to investigate whether cirrhotic liver repopulation could be triggered by partial liver IR. The cirrhosis was induced by thioacetamide (TAA) in rats. After cirrhosis establishment, TAA was withdrawn. In Experiment 1, only right-half liver was irradiated with single doses of 5 Gy, 10 Gy and 15 Gy, respectively. In Experiment 2, right-half liver was irradiated to 15 Gy, and the left-half to 2.5 Gy, 5 Gy and 7.5 Gy, respectively. The regeneration endpoints, including liver index (LI); mitotic index (MI); liver proliferation index (LPI); PCNA-labeling index (PCNA-LI); serum HGF, VEGF, TGF-α and IL-6, were evaluated on 0 day, 30-day, 60-day, 90-day, 120-day and 150-day after IR. Serum and in situ TGF-ß1 were also measured. In both experimental groups, the IR injuries were sublethal, inducing no more than 9% animal deaths. Upon TAA withdrawal, hepatic regeneration decelerated in the controls. In Experiment 1 except for LI, all other regeneration parameters were significantly higher than those in controls for both right-half and left-half livers. In Experiment 2 all regeneration parameters were also higher compared with those in controls for both half livers. Serum HGF and VEGF were increased compared with that of controls. Both unirradiated and low dose-irradiated cirrhotic liver were able to regenerate triggered by sublethal partial liver IR and higher doses and IR to both halves liver triggered a more enhanced regeneration.

[Expression of PCNA and GST-pi after stereotactic irradiation for liver cirrhosis and hepatocarcinoma in rabbits].

OBJECTIVE: To observe the changes of the cytokines following stereotactic irradiation for hepatocarcinoma with cirrhosis in rabbits. METHODS: Sixteen rabbits with liver cirrhosis and hepatocarcinoma (experimental group) were randomized into two equal groups to receive stereotactic irradiation at single dose of 20 and 30 Gy, respectively. Eight rabbits with hepatocarcinoma (control group) were divided into two equal groups and treated in identical manner. All the rabbits were killed 3 weeks after irradiation, and EV two-step method was used to observe the cytokine changes of proliferating cell nuclear antigen (PCNA) and glutathione S-transferase pi (GST-pi) after irradiation. RESULTS: After irradiation, PCNA and GST-pi expression showed significant difference in the adjacent liver tissue between the experimental and control rabbits with irradiation at 20 Gy (P=0.010), but not with the irradiation dose of 30 Gy (P=1.000). Irradiation at different doses resulted in significant difference in the cytokine expression in the experimental rabbits (P=0.010). In the liver tissue exposed to irradiation, different irradiation doses resulted in significant difference in PCNA and GST-pi protein expression (P=0.010). CONCLUSIONS: For hepatocarcinoma with cirrhosis in rabbits, radiation at the single dose of 30 Gy produces better response than 20 Gy, and PCNA and GST-pi may serve as good indexes for evaluating the therapeutic effect.

Lethal hepatic injury by combined treatment of radiation plus chemotherapy in rats with thioacetamide-induced liver cirrhosis.

PURPOSE: To assess lethal hepatic injury by combined treatment of radiation (RT) plus chemotherapy in a rat model with thioacetamide (TAA)-induced liver cirrhosis. METHODS AND MATERIALS: Male Wistar rats were treated with 0.3 g/L TAA in drinking water. The development of liver cirrhosis was histologically confirmed, and the degree of liver function impairment was assessed by indocyanine green retention test (ICG R15). The established cirrhotic rats were given one of the following treatments: partial liver radiotherapy (25 Gy on about one-third of the whole liver), 5-fluorouracil (5-FU) chemotherapy (50 mg/kg), and combined treatment of partial RT plus 5-FU. The treated rats were closely followed until either death or 30 weeks after the treatment, and the postmortem liver sampling was examined for lethal hepatic injury by the treatments. RESULTS: The rats developed overt liver cirrhosis after 30 weeks of TAA treatment. At that time, the mean ICG R15 level in the TAA-treated rats (TAA-rats) was 14.1% +/- 0.7% compared to 4.6% +/- 0.7% in the control (p < 0.05). The 30-week survival rates in the control and TAA-rats were 100% (5/5) and 75% (6/8), respectively, after partial liver RT (p = 0.72). In the 5-FU chemotherapy group, the survival in TAA-rats was only one-half of that in the controls (100% vs. 50%, p = 0.06). Poor survival in TAA-rats was shown also in the combined group of partial RT plus 5-FU (87.5% vs. 16.7%, p = 0.06). The rats that died before the last observation time showed advanced cirrhosis with areas of lobular collapse, in contrast to the moderate cirrhotic features in those that survived. CONCLUSION: In a rat cirrhosis model with mildly impaired liver function, combined treatment of partial RT plus 5-FU resulted in significantly high incidence of lethal liver injury. The results in this study show that a combined treatment of RT plus chemotherapy in cirrhotic patients should be applied with extreme caution.

[Effects of low intensity infra-red laser irradiation on ultrastructure and proliferation of liver cells in experimental hepatitis and cirrhosis]. / Vliianie nizkointensivnogo lazernogo izlucheniia infrakrasnogo diapazona na ul'trastrukturu i proliferatsiiu kletok pecheni pri éksperimental'nom gepatite i tsirroze.

With the aid of light, electron transmission and scanning electron microscopy and radioautography and stereometry, the influence of low-intensive laser irradiation (LILI) (infrared) was studied in normal rat liver and in experimental cirrhosis and hepatitis. It was revealed that arsenide-gallium laser irradiation causes the change of intracellular structure. These changes show the intensification on their specific function manifest in an increase of relative volume of intracellular structures. The changes of microvessels show the activation of microcirculation. The elevation of the index of the labelled nuclei testify to increased proliferation. The similar influences of LILI on the liver ultrastructure and proliferation in hepatitis and cirrhosis are accompanied by the reduction of the pathological changes of the liver--the hepatocytes oedema, granular, vacuolar and fatty dystrophy.