Segment-specific proximal tubule injury in tripterygium glycosides intoxicated rats.

Tripterygium glycosides (TG), extracted from the Chinese herb Tripterygium wilfordii Hook. f, is a widely used anti-inflammatory and immunosuppressive agent with definite nephrotoxicity. However, its toxic mechanism remained undiscovered.

Effects of 18alpha-glycyrrhizin on the pharmacodynamics and pharmacokinetics of glibenclamide in alloxan-induced diabetic rats.

This paper investigated the effects of 18alpha-glycyrrhizin (18alpha-GL) on the pharmacodynamics and pharmacokinetics of glibenclamide in experimental diabetic rats. 18alpha-GL (25 mg/kg) and/or glibenclamide (1 mg/kg) were given to alloxan-induced diabetic rats for consecutive 5 days. When the rats were co-treated with 18alpha-GL and glibenclamide, fasting plasma glucose concentration was further reduced, plasma insulin content and liver glycogen level were increased markedly as compared with glibenclamide-treated animals.

Changes of multiple biotransformation phase I and phase II enzyme activities in human fetal adrenals during fetal development.

Aim: Fetal adrenal, which synthesizes steroid hormones, is critical to fetal growth and development. Our recent research showed that some xenobiotics could interfere with steroidogenesis and induce intrauterine growth retardation in rats. The study on the characteristics of biotransformation enzymes in fetal adrenals still seems to be important with respect to possible significance in xenobiotic-induced fetal development toxicity.

Fast evaluation of oxidative DNA damage by liquid chromatography-electrospray tandem mass spectrometry coupled with precision-cut rat liver slices.

Objective: To establish a fast and sensitive method for the detection of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in precision-cut rat liver slices by HPLC-MS/MS and to investigate isoniazid (INH) -induced oxidative DNA damage.

Methods: Precision-cut liver slices (300 microm) were prepared from male rats, and incubated with INH (0.018 mol/L) for 2 h after 1 h preincubation.

Expression of epoxygenases belonging to CYP2 family in rat myocardial ischemia/reperfusion injury in vivo.

Objective: To elucidate the expression of epoxygenases belonging to cytochrome P-450 mono-oxygenases (CYP2) family in rat ischemic myocardium at varying reperfusion periods, and the effect of epoxygenase inhibition on the post-ischemic heart.

Methods: The current study was conducted in the Department of Pharmacology, Medical College of Wuhan University, China, between September 2004 and June 2005. Rats were subjected to 40 minutes of myocardial ischemia, followed by 0, 15, 60, and 180 minutes of reperfusion.

Influences of 3-methylcholanthrene, phenobarbital and dexamethasone on xenobiotic metabolizing-related cytochrome P450 enzymes and steroidogenesis in human fetal adrenal cortical cells.

Aim: To explore the influence and possible mechanism of xenobiotics on adrenal steroidogenesis during fetal development.

Methods: Primary human fetal adrenal cortical cells were prepared, cultured and treated with 3-methylcholanthrene, phenobarbital and dexamethasone. The activities of 7-ethoxyresorufin O-dealkylase, benzphetamine, aminopyrine and erythromycin N-demethylases were measured by enzyme assays.

[Activation of the immunologic function of rat Kupffer cells by the polysaccharides of Angelica sinensis].

Aim: To observe the influence of polysaccharides of Angelica sinensis (ASP) on the immunologic function of rat Kupffer cells.

Methods: Normal rat Kupffer cells were treated with ASP in vitro. Absorbance at 540 nm ( A540) of neutral red absorption and supernatant NO, TNF-alpha in the cells were measured to evaluate the immunologic function of Kupffer cells; LDH leakage was measured to estimate the severity of cellular damage; Rats were given ASP 0.

CYP2E1 mediated isoniazid-induced hepatotoxicity in rats.

Aim: To investigate the role of CYP2E1 in isoniazid (INH)-induced hepatotoxicity and the influence of rifampicin (RFP) on INH-induced liver injury.

Methods: Rats were treated with INH alone (100 mg/kg, ip) or co-administered with RFP (100 mg/kg, ig) for 10 d and 21 d. Hepatotoxicity was assayed by plasma enzymes (sALT, sAST) and histopathological examinations.

[Antagonistic effect of sodium ferulate on glycerol-induced renal oxidative injury in mice].

Aim: To investigate the effect of sodium ferulate (SF) on glycerol-induced renal injury.

Methods: Glycerol solution 50% was injected intramuscularly to establish a model of acute tubular necrosis in mice. SF was administered intraperitoneally at the dose of 100-200 mg.

[The effects of silymarin on hepatic microsomal and mitochondrial membrane fluidity in mice].

Objective: To observe the effects of silymarin on hepatic microsomal and mitochondrial membrane fluidity in mice.

Method: Liver microsomal and mitochondrial membranes were labled by ANS and DPH. Membrane fluorensent intensity (F), fluorensent polarization(P) and microviscosily(eta) of liver microsome and mitochondria were determined.

[Effects of Angelica sinensis polysaccharides on hepatic drug metabolism enzymes activities in mice].

Objective: To study the effects of Angelica sinensis Polysaccharides (ASP) on the hepatic drug metabolism enzymes activities in normal mice and those prednisolone (PSL)-induced liver injury.

Method: The activities of phase II enzymes (GSH-related enzymes) and cytochrome P450 enzymes were measured by biochemical method.

Result: ASP increased the activities of glutathione S-transferase in liver microsomes and mitochondria.

In vitro metabolic characteristics of cytochrome P-450 2A6 in Chinese liver microsomes.

Aim: To investigate the metabolic characteristics of cytochrome P-450 C YP2A6 in human liver microsomes.

Methods: Cytochrome P-450 enzyme activities were measured by biochemical assays. Xenobiotics were employed to observe their effects on CYP2A6 in vitro.