BACKGROUNDUnder an insulin resistance (IR) state, overproduction of reactive oxygen species (ROS) may be playing a major role in the pathogenesis of endothelial dysfunction, hypertension and atherosclerosis. Recently, increasing attention has been drawn to the beneficial effects of heme oxygenase-1 (HO-1) in the cardiovascular system. This study aimed to investigate the effects of HO-1 on vascular function of thoracic aorta in IR rats and demonstrate the probable mechanisms of HO-1 against endothelial dysfunction in IR states.

METHODSSprague-Dawley (SD) rats fed with high-fat diet for 6 weeks and the IR models were validated with hyperinsulinemic-euglycemic clamp test. Then the IR rat models (n = 44) were further randomized into 3 subgroups, namely, the IR control group (n = 26, in which 12 were sacrificed immediately and evaluated for all study measures), a hemin treated IR group (n = 10) and a zinc protoporphyrin-IX (ZnPP-IX) treated IR group (n = 8) that were fed with a high-fat diet. Rats with standardized chow diet were used as the normal control group (n = 12). The rats in IR control group, hemin treated IR group and ZnPP-IX treated IR group were subsequently treated every other day with an intraperitoneal injection of normal saline, hemin (inducer of HO-1, 30 micromol/kg) or ZnPP-IX (inhibitor of HO-1, 10 micromol/kg) for 4 weeks. Rats in the normal control group remained on a standardized chow diet and were treated with intraperitoneal injections of normal saline every other day for 4 weeks. Systolic arterial blood pressure (SABP) was measured by tail-cuffed microphotoelectric plethysmography. The blood carbon monoxide (CO) was measured by blood gas analysis. The levels of nitric oxide (NO), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS), blood glucose (BG), insulin, total cholesterol (TC) and triglyceride (TG) in serum, and the levels of total antioxidant capacity (TAOC), malondialdehyde (MDA) and superoxide dismutase (SOD) in the aorta were measured. The expression of HO-1 mRNA and HO-1 protein in aortal tissue were detected by semi-quantitative RT-PCR and Western blot. The vasoreactive tensometry was performed with thoracic aortic rings (TARs).

RESULTSCompared with the normal control group, the levels of SABP, BG, insulin, TC, TG, NO, iNOS and MDA were higher, while the levels of CO, TAOC, SOD and eNOS were lower in IR control rats. After treatment of IR rats for 4 weeks a more intensive expression of HO-1 mRNA and HO-1 protein were observed in hemin treated IR group compared with the normal control group. And compared with 4-week IR control rats, the levels of CO, TAOC, SOD and eNOS were increased, while the levels of SABP and iNOS activity were lower in the hemin treated IR group. Administration of hemin in IR rats appeared to improve the disordered vasorelaxation of TARs to acetylcholine (ACh). Alternatively, the reverse results of SABP, CO, TAOC, SOD, iNOS and vasorelaxation responses to ACh were observed in IR rats with administration of ZnPP-IX.

CONCLUSIONSThe endothelial dysfunction in the aorta is present in the IR state. The protective effects of HO-1 against aortic endothelial dysfunction may be due to its antioxidation and regulative effect of vasoactive substances. It is proposed that hemin, inducer of HO-1, could be a potential therapeutic option for vascular dysfunction in IR states.

Animals ; Aorta ; drug effects ; physiology ; Carbon Monoxide ; blood ; Endothelium, Vascular ; drug effects ; physiology ; Enzyme Induction ; drug effects ; Heme Oxygenase-1 ; analysis ; biosynthesis ; genetics ; Hemin ; pharmacology ; Insulin Resistance ; Male ; Nitric Oxide ; blood ; Oxidative Stress ; Rats ; Rats, Sprague-Dawley ; Systole ; drug effects

OBJECTIVETo investigate the change in the antibiotic resistant spectrum of Pseudomonas aeruginosa (PA) isolated from burn wounds and the production of inducible beta-lactamase.

METHODSVITEK-AMS system (total automatic bacterial identification and drug sensitivity system) and E-test concentration gradient were employed to perform bacterial identification and antibiotic sensitivity tests. K-B method was applied to detect inducible enzyme.

RESULTSThe resistance of PA to Cephalosporin and Imipenem was increased in the past 4 years from June of 1996 to June of 2000. Whereas the resistance to Cefoperazone/Sulbactam was least. There was an obvious difference of the resistance of PA to antibiotics during the 4 years (P < 0.05). The resistant rate to Imipenem ranged from 20% to 40%. PA was able to produce inducible enzymes among 120 strains of wild type of PA occupying 72.5% with Imipenam as the inducing agent.

CONCLUSIONThe analysis of the antibiotic resistance of PA and the detection of inducible enzymes could be monitored from time to time and helpful in the correction of the use of antibiotics. Constant monitoring of antibiotic resistance might be beneficial to the prevention of outbreak of epidemics of PA infection in a burn unit.

Burns ; microbiology ; Cephalosporins ; pharmacology ; Drug Resistance, Bacterial ; Enzyme Induction ; Humans ; Imipenem ; pharmacology ; Microbial Sensitivity Tests ; Pseudomonas aeruginosa ; drug effects ; isolation & purification

Neuroleptic malignant syndrome (NMS), a potentially fatal adverse reaction to neuroleptics, is known to occur more often in the initial stage of antipsychotic treatment. We describe a patient with chronic schizophrenia who, in a few days after the addition of antituberculotic drugs to his antipsychotic regimen, developed probable NMS without pyrexia. We reasoned that rifampin, a strong hepatic enzyme inducer, decreased the plasma chlorpromazine concentration of the patient, with the result of cholinergic hyperactivity and finally, the symptoms of NMS. Therefore, physicians should be aware of drug interactions and the likelihood of NMS, and consider antipsychotic dose adjustment when prescribing drugs that may influence pharmacokinetic properties of antipsychotics in a patient with schizophrenia receiving long-term antipsychotic treatment.
Adult ; Antitubercular Agents/*adverse effects ; Chlorpromazine/*adverse effects ; Creatine Kinase/blood ; Drug Interactions ; Enzyme Induction/drug effects ; Humans ; Male ; Neuroleptic Malignant Syndrome/*etiology ; Rifampin/*adverse effects ; Schizophrenia/*drug therapy

The effects of insulin on ATP-citrate lyase, its mRNA in cytosol, and the transcriptional activity in nuclei of diabetic rat liver were studied. Experimental diabetes was induced by an intraperitoneal injection of streptozotocin, and livers were removed from rats at 0, 1, 3, 6, 16, and 72 hours after the administration of insulin. ATP-citrate lyase began to increase at 16 hours, and continuously increased until 72 hours. The amount of mRNA encoding ATP-citrate lyase increased abruptly at 16 hours, then decreased to near basal level in 72 hours. No change in the transcription rate was observed until 3 hours after insulin administration. However, the activity increased 4-fold at 6 hours and 7-fold at 16 hours, 16-fold at 6 hours and 28-fold at 16 hours when pGACL1 and pGACL2 were used as probes, respectively, preceding the increase in the amounts of mRNA and the enzyme. It is suggested that the increase in the amount of ATP-citrate lyase by insulin is primarily due to the increase in the transcriptional activity of the gene in nuclei, which results in the subsequent increase in the amount of mRNA for the biosynthesis of ATP-citrate lyase in cytosol.
ATP Citrate (pro-S)-Lyase/*biosynthesis/genetics ; Animal ; Cell Nucleus/enzymology ; Cytosol/enzymology ; Diabetes Mellitus, Experimental/*enzymology ; Enzyme Induction/drug effects ; Insulin, Isophane/*pharmacology ; Liver/*enzymology ; Male ; RNA, Messenger/drug effects ; Rats ; Rats, Sprague-Dawley ; Transcription, Genetic/drug effects

This study is to investigate the effect of curcumin on the induction of glutathione S-transferases (GST) and NADP(H):quinone oxidoreductase (NQO) and explore their possible molecular mechanism. The activity of GST, NQO and cellular reduced glutathione (GSH) content were measured by spectrophotometrical methods. Cellular changes in the distribution of NF-E2 related factor 2 (Nrf2) were detected by Western blotting analysis. Nrf2-AREs (antioxidant-responsive elements) binding activity was examined by electrophoretic mobility shift assay (EMSA). Treatment of HT-29 human colon adenocarcinoma cells with curcumin dramatically induced the activity of GST and NQO at the range of 10-30 micromol x L(-1). Curcumin exposure caused a significant increase in cellular GSH content rapidly as early as 3 h. Moreover, curcumin triggered the accumulation of Nrf2 in nucleus, and increased Nrf2 content in ARE complexes. These results demonstrated that induction of GST and NQO activity by curcumin may be mediated by translocation of transcription factor Nrf2 from cytoplasm to nuclear and increased binding activity of Nrf2-ARE complexes.
Antineoplastic Agents ; pharmacology ; Antioxidants ; metabolism ; Cell Nucleus ; metabolism ; Curcumin ; pharmacology ; Enzyme Induction ; drug effects ; Glutathione ; metabolism ; Glutathione Transferase ; metabolism ; HT29 Cells ; Humans ; NAD(P)H Dehydrogenase (Quinone) ; metabolism ; NF-E2-Related Factor 2 ; metabolism ; Response Elements ; drug effects ; Signal Transduction

The present study was designed to explore the influence of water extracts of Atractylodes lancea rhizomes on the toxicity and anti-inflammatory effects of triptolide (TP). A water extract was prepared from A. lancea rhizomes and co-administered with TP in C57BL/6 mice. The toxicity was assayed by determining serum biochemical parameters and visceral indexes and by liver histopathological analysis. The hepatic CYP3A expression levels were detected using Western blotting and RT-PCR methods. The data showed that the water extract of A. lancea rhizomes reduced triptolide-induced toxicity, probably by inducing the hepatic expression of CYP3A. The anti-inflammatory effects of TP were evaluated in mice using a xylene-induced ear edema test. By comparing ear edema inhibition rates, we found that the water extract could also increase the anti-inflammatory effects of TP. In conclusion, our results suggested that the water extract of A. lancea rhizomes, used in combination with TP, has a potential in reducing TP-induced toxicity and enhancing its anti-inflammatory effects.
Animals ; Anti-Inflammatory Agents ; isolation & purification ; pharmacology ; Atractylodes ; chemistry ; Cytochrome P-450 Enzyme System ; genetics ; Diterpenes ; toxicity ; Edema ; chemically induced ; pathology ; Enzyme Induction ; drug effects ; Epoxy Compounds ; toxicity ; Gene Expression Regulation ; drug effects ; Herb-Drug Interactions ; Liver ; drug effects ; pathology ; Male ; Mice ; Mice, Inbred C57BL ; Phenanthrenes ; toxicity ; Plant Extracts ; isolation & purification ; pharmacology ; Plants, Medicinal ; chemistry ; Rhizome ; chemistry ; Water ; chemistry

Unmethylated CpG oligodeoxynucleotides (CpG ODNs) activate immune cells to produce immune mediators. This study demonstrates that in murine macrophage RAW 264.7 cells, CpG ODN-mediated matrix metalloproteinase-9 (MMP-9) expression is regulated at transcriptional level and requires de novo protein synthesis. Inhibition of ERK and p38 MAPK, but not JNK, results in significant decrease of CpG ODN-induced MMP-9 expression. We found that endosomal maturation inhibitors, chloroquine and bafilomycin A, block CpG ODN-induced ERK and p38 MAPK activation and the subsequent MMP-9 expression. We also observed that CpG ODN induces NF-kappa B activation and NF-kappa B is a downstream target of p38 MAPK. Taken together, our data demonstrate that CpG ODN triggers MMP-9 expression via TLR-9 dependent ERK and p38 MAPK activation followed by NF-kappa B activation.
Animals ; Cell Line ; Enzyme Activation/drug effects ; Enzyme Induction/drug effects ; Matrix Metalloproteinase 9/*biosynthesis ; Mice ; Mitogen-Activated Protein Kinase 1/antagonists & inhibitors/metabolism ; Mitogen-Activated Protein Kinase 3/antagonists & inhibitors/metabolism ; Mitogen-Activated Protein Kinases/*metabolism ; NF-kappa B/*metabolism ; Oligodeoxyribonucleotides/*pharmacology ; Signal Transduction/drug effects ; Toll-Like Receptor 9/antagonists & inhibitors/*metabolism ; p38 Mitogen-Activated Protein Kinases/antagonists & inhibitors/metabolism

The present study was undertaken to explore whether retinoids, which are known to have immunomodulatory actions, could attenuate tumor necrosis factor-alpha (TNF)-stimulated inducible nitric oxide synthase (iNOS) expression in 3T3-L1 adipocytes. Adipocytes incubated with TNF induced dose- and time-dependent accumulation of nitrite in the culture medium through the iNOS induction as confirmed by Western blotting. Treatment of cells with TNF in the presence of all-trans-retinoic acid (RA) significantly decreased their ability to produce nitrite and iNOS induction. Both 13-cis- and all- trans-RA-induced suppression was dose-dependent, and all-trans-RA was somewhat potent than 13-cis-RA. The inhibitory effect of RA on TNF-induced iNOS induction was reversible, completely recovered after 2 days, and was exerted through the inhibition of NF-kappaB activation. TNF also suppressed the lipoprotein lipase (LPL) activity of 3T3-L1 adipocytes. RA could not reverse the TNF- induced LPL suppression at RA levels causing near complete inhibition of the TNF-induced NO production. These results indicate that RAs attenuate iNOS expression reversibly in TNF-stimulated 3T3-L1 adipocytes, and that the TNF- induced LPL suppression is not the result of NO overproduction.
3T3 Cells ; Adipocytes/drug effects/*enzymology/metabolism ; Animals ; Cells, Cultured ; Enzyme Induction/drug effects ; Enzyme Inhibitors/pharmacology ; Lipoprotein Lipase/drug effects/metabolism ; Mice ; NF-kappa B/antagonists & inhibitors ; Nitric Oxide/metabolism ; Nitric-Oxide Synthase/*antagonists & inhibitors/*metabolism ; Tretinoin/*pharmacology ; Tumor Necrosis Factor/pharmacology

OBJECTIVETo design and make trial of a new therapy for Gaucher disease.

METHODSA substrate analogue of beta-Glc (glucocerebroside analogue, GCA) was used as a molecular chaperon. Normal and mutant skin fibroblasts were cultured with or without GCA. The activity of beta-Glc was assayed by fluorescent enzymologic techniques. The amount of beta-Glc was determined using Western blot. The beta -Glc was localized by double cell stain experiment. The degradation of glucocerebroside was assessed by thin layer chromatography (TLC) experiment using 14C-Serine.

RESULTSIt was found that GCA could enhance the activity and amount of beta-Glc with F213I mutation. It also promoted the beta-Glc with F213I mutation to the lysosome and accelerated the degradation of glucocerebroside.

CONCLUSIONThe low molecular compound analogous to beta-Glc substrate (GCA ) may be a new therapeutic strategy for Gaucher's disease with F213I mutation.

Amino Acid Substitution ; Blotting, Western ; Cells, Cultured ; Enzyme Induction ; drug effects ; Gaucher Disease ; drug therapy ; enzymology ; genetics ; Glucosylceramidase ; biosynthesis ; genetics ; metabolism ; Glucosylceramides ; metabolism ; pharmacology ; Humans ; Immunohistochemistry ; Mutation ; Substrate Specificity

Increased expression of Transglutaminases 2 (TGase 2, TGase C) was observed in PC-14 human lung cancer cells in association with doxorubicin resistance and the reduction of the enzyme expression was correlated with the increasing cytotoxicity of the drug (Han and Park, 1999). Hydrogen peroxide was suggested to be a key mediator for doxorubicin-induced DNA fragmentation leading to apoptosis. A possible role of hydrogen peroxide as a putative mediator of TGase 2 expression in the doxorubicin sensitive PC-14 cells was examined. TGase 2 expression was increased in PC-14 cells treated with doxorubicin in a dose-dependent manner resulting in the concomitant increase of reactive oxygen species. The rise of TGase 2 expression by doxorubicin treatment was inhibited by N-acetylcysteine or glutathione treatment, while direct addition of hydrogen peroxide to PC-14 cells induced TGase 2 expression. These results suggest that generation of hydrogen peroxide induced by doxorubicin treatment is one of the key factors in an enhancement of TGase 2 expression in PC-14 cells.
Acetylcysteine/pharmacology ; Antineoplastic Agents/pharmacology* ; Doxorubicin/pharmacology* ; Enzyme Induction ; Gene Expression Regulation, Enzymologic ; Glutathione/pharmacology ; Human ; Hydrogen Peroxide/pharmacology ; Hydrogen Peroxide/metabolism* ; Lung Neoplasms/enzymology* ; Protein-Glutamine gamma-Glutamyltransferase/biosynthesis* ; Reactive Oxygen Species/metabolism ; Tumor Cells, Cultured/drug effects