Recovery of hepatic function determined by cytochrome P450-dependent drug metabolism lags after compensatory hepatic volume changes after portal vein ligation in rats.
BACKGROUND
Clinically, portal vein embolization has been proven to be useful as a preoperative treatment for major hepatic surgeries with impaired liver function. However, its effects on the metabolism and elimination of various drugs after portal vein embolization or ligation remain to be elucidated.


METHODS
A portal vein branch that perfuses the central and left lobes of the liver of male Wistar rat was ligated, and changes in the weights of ligated and nonligated lobules as well as hepatic levels and activities of cytochrome P450 (CYP) isoforms, such as CYP3A2 and CYP2C11, were determined. To evaluate in vivo the effect of PVL on hepatic drug metabolism, the narcotic activity (sleep time) of midazolam, a specific substrate for CYP3A2, was measured.


RESULTS
Although plasma levels of alanine aminotransferase and hepatic weight returned to basal levels at day 7 after the portal vein ligation, hepatic activities of CYP3A2 and CYP2C11 still remained low (53% and 54% of control levels, respectively), and returned to their initial levels after about day 14. The metabolism of midazolam was prolonged by approximately three times at day 7 after ligation and returned to basal levels at day 14.


CONCLUSIONS
Because hepatic CYP-dependent drug metabolism by CYP isoforms recovered more slowly than the apparent recovery of hepatic volume and plasma alanine aminotransferase levels, the therapeutics of drugs metabolized by the CYP isoforms should be used carefully in patients who receive major hepatectomy with portal vein branch embolization.
Department of Hepato-Biliary Pancreatic Surgery, Osaka City University Graduate School of Medicine, Osaka, Japan. takemura@med.osaka-cu.ac.jp
Shigekazu
S
Takemura
Yukiko
Y
Minamiyama
Kazuhiro
K
Hirohashi
Shoji
S
Kubo
Yoshihiko
Y
Funae
Hiroaki
H
Kinoshita
D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D015153:Blotting, Western; D051544:Cytochrome P-450 CYP3A; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism*; D000072467:Cytochrome P450 Family 2; D004621:Embolization, Therapeutic / Q000009:adverse effects; D008026:Ligation; D008099:Liver / Q000033:anatomy & histology* / Q000098:blood supply / Q000502:physiology*; D008297:Male; D008565:Membrane Proteins / Q000378:metabolism; D008862:Microsomes, Liver / Q000201:enzymology; D008874:Midazolam / Q000378:metabolism / Q000494:pharmacology; D009929:Organ Size; D004364:Pharmaceutical Preparations / Q000378:metabolism*; D011169:Portal Vein / Q000601:surgery*; D051381:Rats; D017208:Rats, Wistar; D012890:Sleep / Q000187:drug effects; D039181:Steroid 16-alpha-Hydroxylase / Q000378:metabolism
D008565:Membrane Proteins; D004364:Pharmaceutical Preparations; D003577:Cytochrome P-450 Enzyme System; D001189:Aryl Hydrocarbon Hydroxylases; C450279:CYP2C11 protein, rat; C465260:Cyp3a2 protein, rat; D051544:Cytochrome P-450 CYP3A; D000072467:Cytochrome P450 Family 2; D039181:Steroid 16-alpha-Hydroxylase; D000410:Alanine Transaminase; D008874:Midazolam