Phenacetin O-deethylation is a useful tool for evaluation of hepatic functional reserve in rats with CCl(4)-induced chronic liver injury.

Mortality of liver resection is as high as 3.1% to 25% in patients with chronic liver disease. Evaluation of hepatic functional reserve is critical for the prediction of risk of postoperation death. Phenacetin O-deethylation is a marker reaction of cytochrome P4501A2 (CYP1A2) activity. In this study, our aim is to investigate whether phenacetin O-deethylation is a useful tool for the evaluation of hepatic functional reserve in rats with chronic liver injury. Rat model for chronic liver injury was established by subcutaneous administration of 50% CCl(4), 1 mL/kg twice per week for 12 wk. Hepatic CYP1A2 activity, content, and mRNA expression were determined (n = 10). Effects of 15%, 30%, and 45% hepatectomy on phenacetin O-deethylation were evaluated in the rats (n = 5 in each group). Additionally, the correlation of risk of death after 70% hepatectomy with phenacetin O-deethylation was studied in 27 rats with chronic liver injury. Compared with normal controls, CYP1A2 activity, content, and mRNA expression decreased 33%, 60%, and 50% in the rats with chronic liver injury (P < 0.05), respectively. Following the increasing of liver-resected size, CYP1A2 activity decreased proportionally (r(s) = -0.877, P < 0.05). Six of 27 rats with chronic liver injury died within 7 d after 70% hepatectomy. Phenacetin metabolism was impaired more severely in 6 rats that died than in 21 living rats (P < 0.05). Phenacetin O-deethylation is a useful tool for the evaluation of hepatic functional reserve in the rats with CCl(4)-induced chronic liver injury.