Résumé
Objective To observe the changes of blood fentanyl concentration in rats during anhepatic phase by treatment of large dose of dexamethasone and to investigate the extrahepatic metabolism of fentanyl. Methods Thirty rats were randomly divided into 3 groups (n=10 in each group): normal control group (Group A), anhepatic phase group (Group B), anhepatic phase+dexamethasone treatment group (Group C). The hepatic portal of rats was dissociated and closed in Group B. In Group C, 20 mg/kg of dexamethasone was infused 1 h before the occlusion of hepatic portal. After intravenous injection of 20 ?g/kg fentanyl each time, the blood samples were collected. The fentanyl blood concentration was analyzed by HPLC. Results The blood fentanyl concentration of anhepatic phase dropped more slowly in Group B than Group C (P0.05). Conclusion The liver is the main organ for fentanyl metabolism. There is the extrahepatic metabolism for fentanyl and dexamethasone can enhance the extrahepatic metabolism of fentanyl.
Résumé
Objective To observe the changes of propofol blood concentrations in rats during anhepatic phase by continuous constant-speed infusion of propofol and to investigate the extrahepatic metabolism of propofol and the effects of lungs on the extrahepatic metabolism of propofol. Methods When the continuous constant-speed transfusion of propofol was carrying out through the left deep cervical vein, the blood samples of 100 ?l were withdrawn simultaneously from the right deep cervical artery and vein at the flowing time points: 5 min before the dissociation of hepatic portal, immediate devascularization of the hepatic portal, 15 min, 30 min and 60 min after devascularization of the hepatic portal. The propofol blood concentrations were analyzed by HPLC. Results At 15 min, 30 min and 60 min after the devascularization of the hepatic portal, the propofol blood concentrations in the right deep cervical artery and vein were significantly higher than that at 5 min before the dissociation of hepatic portal and immediate devascularization of the hepatic portal (P