| Chan WH |
------>authors3_c= ------>paper_class1=1 ------>Impact_Factor=2.425 ------>paper_class3=2 ------>paper_class2=1 ------>vol=97 ------>confirm_bywho=chlin ------>insert_bywho=rmchen ------>Jurnal_Rank=36.4 ------>authors4_c= ------>comm_author= ------>patent_EDate=None ------>authors5_c= ------>publish_day=15 ------>paper_class2Letter=None ------>page2=358 ------>medlineContent= ------>unit=E0200 ------>insert_date=20061010 ------>iam=3 ------>update_date=None ------>author=??? ------>change_event=4 ------>ISSN= ------>authors_c= ------>score=500 ------>journal_name=British Journal of Anaesthesia ------>paper_name=Propofol metabolism is enhanced after repetitive ketamine administration in rats: the role of cytochrome P-450 2B induction ------>confirm_date=20061222 ------>tch_id=088008 ------>pmid=16845130 ------>page1=351 ------>fullAbstract=BACKGROUND: In a series of ex vivo and in vivo studies we investigated the ability of repetitive ketamine administration to alter the metabolism and anaesthetic effect of propofol and the role of ketamine-mediated P-450 2B induction in rats. METHODS: Male Wistar rats were pretreated with 80 mg kg(-1) ketamine i.p. twice daily for 4 days. Pentoxyresorufin O-dealkylation (PROD), P-450 2B protein and mRNA were determined. Residual propofol concentration was measured after incubating hepatic microsomes with 100 muM propofol. Sleeping times induced by i.p. 80 mg kg(-1) propofol were determined. Orphenadrine, a P-450 2B inhibitor, was added in both ex vivo and in vivo studies. Finally, serial whole blood propofol concentrations were determined after i.v. infusion of 15 mg kg(-1) propofol. RESULTS: Ketamine pretreatment produced 5.4-, 3.4- and 1.7-fold increases in hepatic PROD activity, P-450 2B protein and mRNA, respectively. Residual propofol concentration was 46% lower after incubation with microsomes from ketamine-pretreated rats than in the control group. The addition of orphenadrine to ketamine-pretreated microsomes produced an increase in residual propofol concentration in a concentration-dependent manner. Ketamine pretreatment reduced propofol sleeping time to 12% of the control, which was reversed by orphenadrine. The whole blood propofol concentration in ketamine-pretreated rats was significantly lower than that of control rats at 1, 2, 4 and 8 min after cessation of propofol infusion. CONCLUSIONS: Repetitive ketamine administration enhances propofol metabolism and reduces propofol sleeping time in rats. We suggest that P-450 2B induction may produce ketamine-propofol interaction in anaesthetic practice. ------>tmu_sno=None ------>sno=14131 ------>authors2=Chen TL ------>authors3=Chen RM ------>authors4=Sun WZ ------>authors5=Ueng TH ------>authors6= ------>authors6_c= ------>authors=Chan WH ------>delete_flag=0 ------>SCI_JNo=None ------>authors2_c= ------>publish_area=0 ------>updateTitle=Propofol metabolism is enhanced after repetitive ketamine administration in rats: the role of cytochrome P-450 2B induction. ------>language=2 ------>check_flag=None ------>submit_date=None ------>country=None ------>no=3 ------>patent_SDate=None ------>update_bywho=None ------>publish_year=2006 ------>submit_flag=None ------>publish_month=7 |