Down-regulation of rat hepatic microsomal cytochromes P-450 in microvesicular steatosis induced by orotic acid

Microvesicular steatosis is an important component of the overall pathogenesis of drug-mediated liver injury. Although mitochondrial damage has a role in the development of microvesicular steatosis, the consequences of fatty change for hepatic gene function are unclear. The present study was undertaken to evaluate hepatic cytochrome P-450 (CYP) function in a rat model of microvesicular steatosis produced by the intake of diets containing 1% orotic acid (OA) that were administered for 5, 10, or 21 days. Hepatic triglyceride levels were increased to 3-fold of control after 5 days and were elevated further at 10 and 21 days. Cholesterol and phospholipid contents were increased after 10 and 21 days but not by 5 days of feeding. Microsomal androst-4-ene-3,17-dione hydroxylation activities mediated by CYP2C11 (16alpha-hydroxylation) and CYP3A2 (6beta-hydroxylation) were decreased in liver from OA-fed rats for only 5 days, whereas CYP2A1/2-mediated steroid 7alpha-hydroxylation was decreased after 10 days; these observations were complemented by immunoblot analysis that demonstrated the impaired expression of the corresponding CYP proteins. CYP2C11 mRNA, the major CYP in male rat liver, was down-regulated in steatotic liver to 52 +/- 4% of control. Thus, microvesicular steatosis induced by short-term intake of OA-containing diets is histologically similar to that produced by hepatotoxic drugs and produces the rapid down-regulation of constitutive CYPs in rat liver. Analogous processes of lipid deposition in human liver after drug- or disease-related injury could precipitate adverse effects during subsequent drug therapy.     

失血性休克大鼠器官组织中促炎细胞因子表达及释放的时相性研究

目的探讨休克后促炎细胞因子表达释放的时相性变化。方法80只SD大鼠被随机分为失血性休克组（40只）和对照组（40只）。于休克后30、60和90min及复苏后30min和90min各处死8只大鼠，采用逆转录-聚合酶链反应（RT～PCR）检测失血性休克后各时间点肠、肝、肺组织内肿瘤坏死因子-α（TNF—α）、白细胞介素-1β（IL-1β）、IL-6的mRNA表达，采用酶联免疫吸附试验（ELISA）双抗体夹心法测定血清中TNF—α、IL-6的含量。结果①休克30min时，肠、肝、肺组织中促炎细胞因子的mRNA表达均未见升高；休克60min肠道首先出现TNF—α mRNA表达升高（P〈0．05），而肝脏在休克90min时表达开始升高（P〈0．01），肺脏则在复苏后30min表达开始升高（P〈0．05）。复苏后90min肠、肝、肺组织中TNF—α mRNA表达仍高于对照组（P均〈0．01）。TNF—α mRNA在肠、肝、肺内的表达升高最早，其后才是IL-1β mRNA和IL-6 mRNA。②休克30min门静脉血和下腔静脉血中TNF—α、IL-6的含量与对照组比较差异均无显著性，而休克60min时门静脉血中TNF—α含量显著升高（P〈0．05）；休克90min、复苏后30min和90min门静脉血和下腔静脉血中TNF—α、IL-6含量均较对照组显著升高（P均〈0．01）。结论失血性休克时细胞因子的释放顺序县肠道、肝脏和肺脏。椎测存在“肠→肝→肺”细胞因子释放轴。     

The α-tocopherol status and expression of α-tocopherol-related proteins in methionine-choline deficient rats treated with vitamin E

Non-alcoholic fatty liver disease is the most common liver disorder in developed countries, and its incidence is increasing in all population groups. As an antioxidant, vitamin E is effective in the treatment of non-alcoholic fatty liver disease, although the mechanism is still unclear. Methionine-choline deficient Wistar rats (n = 5) used as an experimental model of non-alcoholic fatty liver disease were fed a vitamin E-enriched diet (500 mg/kg) for 4 weeks. The effects were assessed by measuring lipid peroxidation, α-tocopherol levels, and the expression of α-tocopherol-related proteins in the liver. In vitamin E-treated methionine-choline deficient rats, lipid peroxidation was reduced, but liver histopathological changes were not improved. Hepatic α-tocopherol levels in these rats were significantly elevated compared to normal rats treated with vitamin E. Expression of liver α-tocopherol transfer protein in vitamin E-treated methionine-choline deficient rats was significantly repressed compared to methionine-choline deficient rats. The expression of liver cytochrome P450 4F2 and ATP-binding cassette transporter protein 1, involved in metabolism and transport of α-tocopherol, respectively, was significantly repressed in vitamin E-treated methionine-choline deficient rats. In methionine-choline deficient rats, vitamin E treatment altered the hepatic α-tocopherol-related protein expression, which may affect α-tocopherol status in the liver, leading to reduced lipid peroxidation.     

The effects of hyperbaric oxygen treatment on oxidant and antioxidants levels during liver regeneration in rats

The effects of hyperbaric oxygen (HBO) therapy on oxidant/antioxidant metabolism are controversial and its effects on hepatic regeneration are not known. In this study, we investigated a possible beneficial effect of HBO therapy on oxidant and antioxidants levels during liver regeneration. To conduct this study, seventy percent hepatectomy was performed on forty-eight Spraggue-Dawley rats and the rats were divided into two equal groups: HBO-treated group and untreated group (non-HBO group). We determined the levels of malondialdehyde (MDA), an oxidative stress marker, and the levels of antioxidant enzymes/reagents, including glutathione (GSH), superoxide dismutase (SOD) activity, copper (Cu) and zinc (Zn), in the remnant liver samples. We also measured mitotic index (MI) and proliferating cell nuclear antigen (PCNA) levels to assess the degree of liver regeneration. HBO treatment significantly decreased MDA levels, whereas it increased SOD activity, GSH and Zn levels. In contrast, Cu levels were lower in the HBO-treated livers than the levels in the untreated remnant livers. The effect of HBO treatment may be mediated by the suppression of certain enzymes that are responsible for lipid peroxidation. In addition, HBO treatment may induce the production of antioxidant enzymes/reagents by remnant liver tissues. The HBO-treated rats maintained their body weights but the untreated rats lost body weights. HBO treatment also increased MI and PCNA levels, indicating HBO treatment enhances liver regeneration. These results indicate that HBO treatment has beneficial effects on liver regeneration by decreasing MDA and by increasing antioxidant activities. We therefore suggest that HBO therapy may be useful after liver resection.     

Role of endogenous nitric oxide in TNF-alpha and IL-1beta generation in hepatic ischemia-repefusion

In the present study, we examined the role of nitric oxide (NO) in early-response cytokine production by using a rat model of hepatic ischemia-reperfusion (HI/R). The left and median lobes of the liver were subjected to 30 min of ischemia, followed by 4 h of reperfusion. Group I and II rats were sham-operated controls that received saline (vehicle) or N(W)-nitro-L-arginine methylester (L-NAME) (10 mg/kg, iv); group III and IV rats were subjected to HI/R and received vehicle or L-NAME (10 mg/kg, iv, 10 min before reperfusion), respectively. Administration of L-NAME to rats subjected to I/R resulted in a fourfold decrease in plasma NO levels, accompanied by a marked increase of plasma alanine aminotransferase (ALT) activity relative to group III. These changes in group IV were associated with elevation of superoxide generation in ischemic liver lobes by 2.1-fold and circulating leukocyte number by 1.42-fold, compared with group III. Normalized for expression of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) messenger ribonucleic acid (mRNA), expression of tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) mRNA in ischemic liver of group IV was augmented by 207% and 175% compared with Group III. The expression of (iNOS) mRNA was also increased (223%) relative to group III. Moreover, in group IV, plasma TNF-alpha levels at 4 h of reperfusion and IL-1beta levels at 90 min and 4 h of reperfusion were significantly increased compared with group III. No statistically significant changes were observed between groups I and II in plasma ALT activity, plasma NO levels, circulating leukocyte counts, superoxide generation in the ischemic lobes of liver, and plasma TNF-a and IL-1beta concentrations. The observed enhancement of I/R injury by L-NAME is consistent with the hypothesis that endogenous NO down-regulates TNF-alpha and IL1beta generation, thereby decreasing HI/R injury.     

热休克蛋白70对感染性脑水肿大鼠白介素和肿瘤坏死因子的影响及意义

目的 :探讨白介素和肿瘤坏死因子在感染性脑水肿时的变化及热休克蛋白 70 (HSP70 )对它们的影响。方法 :将 72只 SD大鼠随机分为正常对照组 (NS)、感染性脑水肿组 (IBE)和热休克处理组 (HSP) ,每组又分为 4、8和 2 4 h3个时间点亚组。采用 Western印迹杂交技术检测各组各时间点的 HSP70的表达 ,采用酶联免疫吸附法 (EL ISA)分别检测 3组大鼠脑组织匀浆中白介素 1β(IL 1β)及肿瘤坏死因子α(TNFα)的含量。结果 :Western印迹杂交分析经密度扫描后结果表明 ,感染性脑水肿及正常大鼠脑组织内均有一定量的 HSP70表达 ,而 HSP组的 HSP70量明显高于 IBE组 (P均 <0 .0 1)。与 NS组比较 ,4、8和 2 4 h IBE组的 TNFα含量明显增加 ,以 8h为最明显 (P均 <0 .0 1) ;而在 4和 8h IBE组中 ,脑组织 IL 1β含量明显增高 ,以 8h增高最明显 (P均 <0 .0 1) ,2 4 h则明显下降 ;热休克反应能降低 IL 1β及 TNFα在脑组织中的含量 (P<0 .0 5或P<0 .0 1)。结论 :IL 1β及 TNFα参与了感染性脑水肿的病理过程 ,HSP70能减轻感染性脑水肿的机制可能与其抑制 IL 1β和 TNFα生成有关。     

Effect of pentylenetetrazol-induced epileptic seizure on the antioxidant enzyme activities, glutathione and lipid peroxidation levels in rat erythrocytes and liver tissues

OBJECTIVES: In order to clarify whether oxidative stress accompanies epilepsy, we examined the effects of pentylenetetrazol (PTZ)-induced epilepsy on the lipid peroxidation and antioxidant enzyme activities in erythrocytes and liver tissues of adult Wistar rats. MATERIALS AND METHODS: The activities of antioxidative enzymes (glucose-6-phosphate dehydrogenase (G-6-PD)), copper, zinc-superoxide dismutase (Cu,Zn-SOD), catalase (CAT), selenium-dependent glutathione peroxidase (Se-GSH-Px) and the levels of reduced glutathione (GSH) and thiobarbituric acid-reactive substances (TBARS) were measured in erythrocytes and liver tissues of pentylenetetrazol (PTZ)-induced epileptic adult Wistar rats. RESULTS: Single PTZ treatment in a convulsive dose of 50 mg/kg significantly reduced the erythrocyte Cu,Zn-SOD, CAT enzyme activities and GSH levels compared to controls (P < 0.001, P < 0.001, P < 0.05, respectively). Erythrocyte and liver tissue TBARS levels in the epileptic group were significantly higher than controls (P < 0.0001). There was a significant decrease in liver tissue Cu,Zn-SOD activity and GSH levels in the epileptic group (P < 0.0001), whereas significantly higher activities of G-6-PD and Se-GSH-Px were found in the epileptic group. CONCLUSIONS: Our results demonstrate a generalized diminished antioxidant activity and increased TBARS level indicating enhanced oxidative stress in the liver and erythrocytes of epileptic rats. Increased oxidative stress in the liver of epileptic rats might be due to the activation of the recently found glutamate receptors in the liver. These findings suggest that the use of antioxidants with antiepileptic drugs and new drugs such as type-5 metabotropic glutamate receptor (mGlu5) antagonist (MPEP) might protect erythrocytes and liver tissue against anoxic damage and oxidative stress.     

Apocynin administration prevents the changes induced by a fructose-rich diet on rat liver metabolism and the antioxidant system

In the present study, we investigated the role of NADPH oxidase in F (fructose)-rich-diet-induced hepatic OS (oxidative stress) and metabolic changes, and their prevention by apocynin co-administration. Wistar rats were fed for 21?days on (i) a control diet, (ii) a control diet plus 10% F in the drinking water, (iii) a control diet with apocynin in the drinking water (CA) and (iv) F plus apocynin in the drinking water (FA). Glycaemia, triglyceridaemia, NEFAs (non-esterified fatty acids) and insulinaemia were determined. In the liver, we measured (i) NADPH oxidase activity, and gene and protein expression; (ii) protein carbonyl groups, GSH and TBARSs (thiobarbituric acid-reactive substances); (iii) catalase, CuZn-SOD (superoxide dismutase) and Mn-SOD expression; (iv) liver glycogen and lipid content; (v) GK (glucokinase), G6Pase (glucose-6-phosphatase) and G6PDH (glucose-6-phosphate dehydrogenase) activities; (vi) FAS (fatty acid synthase), GPAT (glycerol-3-phosphate acyltransferase), G6Pase and G6PDH, IL-1β (interleukin-1β), PAI-1 (plasminogen-activator inhibitor-1) and TNFα (tumour necrosis factor α) gene expression; and (vii) IκBα (inhibitor of nuclear factor κB α) protein expression. F-fed animals had high serum TAG (triacylglycerol), NEFA and insulin levels, high liver NADPH oxidase activity/expression, increased OS markers, reduced antioxidant enzyme expression, and increased glycogen, TAG storage and GK, G6Pase and G6PDH activities. They also had high G6Pase, G6PDH, FAS, GPAT, TNFα and IL-1β gene expression and decreased IκBα expression. Co-administration of apocynin to F-fed rats prevented the development of most of these abnormalities. In conclusion, NADPH oxidase plays a key role in F-induced hepatic OS production and probably also in the mechanism of liver steatosis, suggesting its potential usefulness for the prevention/treatment of T2DM (Type 2 diabetes mellitus).     

The effects ofN-acetylcysteine on oxidative stress in organophosphate poisoning model

Organophosphate compounds act by irreversible inhibition of cholinesterase. In addition to their muscarinic, nicotinic, and central nervous system effects, some organophosphate insecticides cause oxidative stress by increasing lipid peroxidation in erythrocytes and by increasing levels of the enzymes Superoxide dismutase and catalase. In this study, the effects of an antioxidant,N-acetylcysteine (NAC), in organophosphate poisoning were investigated. After obtaining Animal Ethics Committee approval, 16 male Wistar rats were divided into 2 groups. Following anesthesia, rats were tracheostomized and mechanically ventilated. Invasive hemodynamic monitoring was begun and all rats were injected with 70 mg/kg of dichlorvos (DDVP) intraperitoneally. The rats in group 1 received placebo intravenous 0.9% NaCl and the rats in group 2 received 150 mg/kg intravenous NAC. Blood samples were obtained before injection of DDVP and 60 minutes after injection to determine levels of malondialdehyde, superoxide dismutase, and catalase. Hemodynamic data and biochemistry test results were compared by analysis of variance and Wilcoxon test.P< .05 was regarded as statistically significant. Superoxide dismutase and malondialdehyde levels were significantly increased in group 1 while no difference was observed in group 2. It was concluded that organophosphate compounds might cause oxidative stress by interfering with antioxidant defense mechanisms in erythrocytes and that NAC might prevent increased lipid peroxidation. In addition to classic treatments, drugs with antioxidant effects might therefore be promising in the treatment of organophosphate poisoning.     

尼莫地平对大鼠烫伤后库普弗细胞白介素-1β和白介素-6产生的抑制作用

目的 :探讨钙离子通道阻断剂尼莫地平对烧伤后库普弗细胞 (KC)合成释放白介素 1β(IL 1β)、IL 6的调控作用 ,为寻找一种有效减轻、控制烧伤后过度全身炎症反应的措施提供理论依据。方法 :内灌注消化、密度梯度离心法分离培养正常 SD大鼠 KC,显微荧光分光光度计复合倒置显微镜技术观察烫伤血清作用下单个 KC细胞内钙 (〔 Ca2 +〕i)变化 ,酶联免疫吸附法 (EL ISA)测定烫伤血清培养的 KC上清中 IL 1β和IL 6的浓度变化。 SD大鼠行 30 %总体表面积 (TBSA) 度烫伤 ,伤后 6 h分离 KC,RNA酶保护分析法测定KC中两种细胞因子 m RNA的表达量 ,并测定血浆细胞因子水平 ;观察尼莫地平存在时上述结果的改变。结果 :与对照组相比 ,烧伤组 KC〔 Ca2 + 〕i峰值及培养上清中 IL 1β、IL 6浓度增加值均显著增加 (P均 <0 .0 1) ,在 1μm ol/L尼莫地平存在时 ,两者均显著减少 (P均 <0 .0 1)。烧伤后 6 h KC中 IL 1β和 IL 6的m RNA表达量及其血浆水平均显著升高 ,静脉予尼莫地平 (40 μg· kg- 1 · h- 1 )后两者均显著减少 (P均 <0 .0 1)。结论 :大鼠严重烧伤后 ,KC合成释放 IL 1β和 IL 6 ,此过程通过细胞内钙离子通道信号传导途径实现。尼莫地平能抑制烧伤后 KC中 IL 1β和 IL 6 m RNA表达 ,使 KC产生 IL 1β、IL 6明显     

Protective effects of rhizoma paridis total saponins on septic rats

OBJECTIVE: To investigate the protective effect of rhizoma paridis total saponins and its mechanism on septic rats. METHODS: Septic model was reproduced by cecal ligation and puncture (CLP) in Wistar rats. Rhizoma paridis total saponins was administered to observe its protective effects on septic rats. Blood was collected to determine serum tumor necrosis factor-alpha (TNF-alpha) and interleukin-1beta(IL-1beta)levels at 2, 6, 12, 24 and 48 hours after operation by means of enzyme-linked immunosorbent assay (ELISA). The pathological changes of lung tissue were observed with light microscope at 72 hours after operation. The peritoneal macrophages (PMZ) in rats were isolated and the release of TNF-alpha and IL-1beta in PMZ after exposure to lipopolysaccharide (LPS, 100 mug/L) were measured by ELISA. RESULTS: Mortality in the rhizoma paridis total saponins group was significantly lower than the CLP group (50.0% vs. 85.0%, P<0.05). The levels of TNF-alphaand IL-1beta in serum were significantly lower than those of the CLP group at the same time (P<0.05 or P<0.01). The degree of inflammatory injury to the lung was much milder than that in the CLP group. In the in vitro experiment, it was shown that rhizoma paridis total saponins in concentrations of 5, 10, 20 and 40 mg/L could inhibit remarkably the release of TNF-alpha and IL-1beta from LPS-stimulated PMZ of rats (all P<0.01). The differences in TNF-alpha levels among the groups showed no statistically significant difference(all P>0.05). The level of IL-1beta in 5 mg/L group was significantly higher than that of the 10 mg/L group (P<0.05), but showed no difference with those of 20 mg/L and 40 mg/L groups (both P>0.05). CONCLUSION: Rhizoma paridis total saponins can protect the CLP rats by inhibiting the activation of rat PMPhi to release cytokines and ameliorating acute lung injury.     

用抗癫痫药物建立大鼠肝损伤的动物模型

目的 探讨抗癫痫药苯巴比妥、卡马西平对大鼠肝脏组织学及牛化指标的影响,建市抗癫痫药引起肝损伤的动物模型.方法 将7～8周龄Wistar大鼠随机分为4组,阳性对照组经腹腔注射四氯化碳（CCl4）原液1mL·kg-1.给药组,分别每日1次经口灌胃给予苯巴比妥（52.08mg·kg-1）,卡马西平（125.00mg·kg-1）,阴性对照组给予等体积的蒸馏水.每周采血检测血清生化指标,连续用药5周后,采血检测血清生化指标,应用光镜进行肝脏病理学研究.结果 （1）病理组织学检查,光镜下阳性对照组大鼠可见广泛的水性样变、空泡样变;苯巴比妥组大鼠可见部分水性样变,肝窦轻度水肿;卡马西平组大鼠可见水性样变.（2）与阴性对照组比较,苯巴比妥组、卡马西平组的肝脏指数有非常显著性差异（P〈0.01）.（3）与阴性对照组比较,苯巴比妥组、卡马西平组的血清丙氨酸氨基转移酶有显著性变化.结论 在治疗剂量范围内,连续服用抗癫痫药苯巴比妥、卡马西平5周可引起机体抗氧化能力降低,肝组织病理学检查可见轻微病理改变,引起大鼠肝损伤.     

Lipid peroxidation and antioxidant status in experimental diabetes.

Oxidative stress is currently suggested as a mechanism underlying diabetes. The present study was designed to evaluate the oxidative stress related parameters in streptozotocin-induced diabetes in rats using different complementary approaches: susceptibility to in vitro oxidation (lipid peroxidation induction in liver homogenate, red blood cells hemolysis), blood antioxidant status (total antioxidant capacity by two approaches), and plasma isoprostane measurement, a new marker of lipid peroxidation in vivo. We have shown that induced liver thiobarbituric acid reactive substances increased after 4 weeks of diabetes, in spite of increased liver vitamin E content. Red blood cells hemolysis was significantly delayed after 4 weeks of diabetes. Plasma antioxidant capacity (AOC) tended to increase after 4 weeks of diabetes and was correlated with plasma vitamin E levels. Total antioxidant activity (TAA) significantly decreased after 1 week and a significant correlation was observed with plasma albumin levels. Plasma isoprostane (8-epiprostaglandinF2alpha) concentrations were not modified significantly 1 week or 4 weeks after the induction of diabetes. Levels of vitamin E in the diet and changes in its distribution among the body seems to play an important role in the development of oxidative stress during diabetes and its consequences.     

Trolox-derivative antioxidant protects against methanol-induced damage

Summary— This paper reports data on the effect of a new antioxidant, U-83836E, on the lipid peroxidation and antioxidant status of liver, red blood cells (RBCs) and blood serum of rats intoxicated with methanol (3.0 g/kg body weight). Methanol administration slightly increased the levels of peroxidation products in the liver, and markedly increased them in RBCs and serum. In contrast, glutathione-peroxidase, glutathione-reductase activity, reduced glutathione concentration and total antioxidant status were decreased. The use of U-83836E, containing a trolox ring, appeared to be beneficial in reducing lipid peroxidation products and in partially in preventing the decrease in glutathione and antioxidant enzymes induced by methanol in liver and serum. These results show that antioxidant U-83836E may partially prevent methanol toxicity.     

Inhibition of mitochondrial beta-oxidation of fatty acids by pirprofen. Role in microvesicular steatosis due to this nonsteroidal anti-inflammatory drug

Administration of pirprofen may produce microvesicular steatosis of the liver in humans. The effects of pirprofen on the mitochondrial beta-oxidation of fatty acids have been investigated in mice. In vitro, addition of 2 mM pirprofen decreased by 50% the formation of [14C]acid-soluble beta-oxidation products, and decreased by 70% the formation of [14C]CO2 upon incubation of hepatic mitochondria with [14C]palmitic acid, ATP, carnitine and coenzyme A. In vivo, administration of pirprofen (2 mmol . kg-1 i.p.), 1 hr before that of [U-14C]palmitic acid, decreased by 70% the exhalation of [14C]CO2 during the next 6 hr. Administration of pirprofen (2 mmol . kg-1 i.p.), 1 hr before the measurement, decreased plasma beta-hydroxybutyrate by 60%, plasma acetoacetate by 30% and blood glucose by 40%. Administration of pirprofen (2 mmol . kg-1 i.p.) 6 hr before sacrifice, doubled hepatic triglycerides content and produced microvesicular steatosis of the liver. We conclude that pirprofen inhibits the mitochondrial beta-oxidation of fatty acids in mice, thus explaining the microvesicular steatosis observed in mice and in some human subjects.     

氧化苦参碱对蛛网膜下腔出血大鼠脑血管痉挛的作用及机制研究

目的探讨氧化苦参碱（OMT）对蛛网膜下腔出血（SAH）大鼠脑血管痉挛的作用及机制的研究。 方法将200只雄性大鼠分成假手术组、SAH组、小剂量组和大剂量组,每组50只。采用枕大池二次注血法制作SAH大鼠模型,假手术组大鼠两次均注入等量生理盐水,其余三组在模型建立后分别给予1 ml的0.9%氯化钠注射液,60和120 mg/kg的OMT腹腔注射。在术后1、3、5、7和10 d每组分别处死10只大鼠,测量四组大鼠基底动脉血管直径,检测基底动脉内皮细胞核因子κB（NF-κB）、胞外信号调节激酶（ERK）1/2、p38丝裂原活化蛋白激酶（MAPK）、c-Jun氨基末端激酶（JNK）的蛋白相对表达量,以及基底动脉内皮细胞白细胞介素1β（IL-1β）、IL-6和肿瘤坏死因子α（TNF-α）的mRNA相对表达水平。 结果术后3、5、7和10 d,四组大鼠基底动脉血管直径（F = 11.897、28.957、14.785、8.381,P均< 0.05）,基底动脉内皮细胞NF-κB（F = 17.289、65.602、43.881、26.998,P均< 0.05）、ERK1/2（F = 204.331、145.948、107.442、30.332,P均< 0.05）、p38MAPK（F = 84.908、116.677、83.735、28.338,P均< 0.05）和JNK（F = 26.809、83.419、56.465、27.756,P均< 0.05）蛋白表达,以及基底动脉内皮细胞IL-1β（F = 66.625、262.620、283.499、218.081,P均< 0.05）、IL-6（F = 38.580、170.657、136.253、58.068,P均< 0.05）和TNF-α（F = 31.290、361.661、101.109、23.940,P均< 0.05）mRNA水平的比较,差异均有统计学意义（P均< 0.05）。其中术后3、5、7和10 d时间点上,假手术组和大剂量组大鼠基底动脉血管直径均较SAH组显著增大（P均< 0.05）,而这两组的基底动脉内皮细胞NF-κB、ERK1/2、p38MAPK和JNK的蛋白表达,以及IL-1β、IL-6和TNF-α的mRNA表达均显著少于SAH组（P均< 0.05）。但小剂量组的以上指标和SAH组比较差异均无统计学意义（P均> 0.05）。 结论OMT可改善SAH大鼠脑血管痉挛,其机制可能与OMT抑制脑血管内皮细胞NF-κB、ERK1/2、p38MAPK和JNK等信号通路,降低大鼠基底动脉血管炎症反应有关。     

Inhibition of nitric oxide synthesis by L-name exacerbates acute lung injury induced by hepatic ischemia-reperfusion.

Hepatic Kupffer cells and pulmonary alveolar macrophages together constitute a macrophage-axis involved in the regulation of regional and systemic inflammatory responses. Systemic inflammatory response syndrome induced by overproduced pro-inflammatory mediators is the major cause of adult respiratory distress syndrome. In the present study, we examined the anti-inflammatory role of nitric oxide (NO) in a rat model of acute lung injury induced by hepatic ischemia-reperfusion (HI/R). The left and median lobes of the liver were subjected to 30 min of ischemia by clamping the relevant branches of hepatic artery and portal vein, followed by a 4-h reperfusion achieved by removal of the vascular clamp. Four groups of animals were studied: sham control + saline; sham control + N(omega)-nitro-L-arginine methyl ester (L-NAME, 10 mg/kg, i.v., 10 min before reperfusion); HI/R + saline; HI/R + L-NAME. Results show that (1) administration of L-NAME to rats subjected to HI/R decreased plasma NO levels; however, the attenuation of NO increased plasma alanine aminotransferase (ALT) activity and superoxide generation in the ischemic lobes of liver, compared to HI/R alone. (2) Inhibition of NO synthesis with L-NAME in rats subjected to HI/R also enhanced systemic inflammatory response as assessed by the increase in the number of circulating leukocytes and levels of plasma tumor necrosis factor-alpha (TNFalpha) and interleukin 1-beta (IL-1beta). (3) The overwhelming systemic inflammatory response induced by administration of L-NAME in rats subjected to HI/R also augmented pulmonary vascular permeability and superoxide generation in the lung tissue. (4) Pulmonary alveolar macrophages isolated from rats subjected to HI/R + L-NAME produced higher levels of TNFalpha and IL-1beta in the supernatant of culture medium than that of rats subjected to HI/R alone. (5) There were no differences between the groups of sham + saline and sham + L-NAME in terms of plasma NO levels and ALT activity, circulating leukocytes, superoxide generation in the liver and lung, lavage protein levels, and TNFalpha and IL-1beta levels in plasma and bronchoalveolar lavage fluid. Our results suggest that inhibition of NO synthesis by L-NAME in rats subjected to HI/R not only augments ischemic liver injury, but also enhances the systemic inflammatory response and exacerbates remote lung injury. The increase in TNFalpha and IL-1beta production by alveolar macrophages may, in part, account for L-NAME-induced enhancement of acute lung injury.     

Effects of caffeic acid phenethyl ester on lipid peroxidation and antioxidant enzymes in diabetic rat heart

OBJECTIVES: The risk for cardiovascular disease is significantly high in diabetes mellitus. Experimental evidence suggests that oxidative stress plays a dominant role in the pathogenesis of diabetes mellitus. Caffeic acid phenethyl ester (CAPE), an active component of propolis, has several biological and pharmacological properties, including antioxidant, anti-inflammatory, anti-carcinogenic, antiviral, and immunomodulatory activities. In light of the antioxidant ability of CAPE, the effects of CAPE on the antioxidative status of cardiac tissue were investigated in streptozotocin (STZ)-induced diabetic rats. DESIGN AND METHODS: Twenty-six rats were randomly divided into three groups: group I, control, nondiabetic rats (n = 9); group II, STZ-induced, untreated diabetic rats (n = 7); and group III, STZ-induced, CAPE-treated diabetic rats (n = 10). In groups II and III, diabetes developed 3 days after intraperitoneal (ip) administration of a single 35 mg kg(-1) dose of STZ. Thereafter, while the rats in group II received no treatment, the rats in group III began to receive a 10 mumol kg(-1) ip dose of CAPE per day. After 8 weeks, the levels of malondialdehyde (MDA) and the activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) in the cardiac tissues of all groups were analyzed. RESULTS: In untreated diabetic rats, MDA markedly increased in the cardiac tissue compared with the control rats (P < 0.05). However, MDA levels were reduced to the control level by CAPE. The activities of SOD and CAT in the untreated diabetic group and the CAPE-treated diabetic group were higher than those of the control group (P < 0.05). Rats in the CAPE-treated diabetic group had reduced activities of SOD and CAT in comparison with the rats in the untreated diabetic group (P < 0.05). There were no significant differences in the activity of GSH-Px between the rats in the untreated diabetic group and the control group. However, the activity of GSH-Px was increased in CAPE-treated diabetic rats compared with the control and untreated diabetic rats (P < 0.05). CONCLUSION: These results reveal that diabetes mellitus increases oxidative stress in cardiac tissue and CAPE has an ameliorating effect on the oxidative stress via its antioxidant property.     

Hepatocellular dysfunction induced by nitric oxide production in hepatocytes isolated from rats with sepsis

In the process of sepsis, the failing organ is not necessarily directly injured or involved in the primary disease process, and the development of distant organ failure may be induced by the host's primed response on an initial insult followed by subsequent insult. We hypothesized that enhancement of nitric oxide (NO) production in the presence of interleukin (IL)-1beta in hepatocytes, isolated under septic conditions, could be implicated in the change in liver energy metabolism, thus resulting in hepatocellular dysfunction. We performed cecal ligation and puncture (CLP group) or a sham operation (sham group) in rats and then isolated hepatocytes from the liver at 6 h postoperatively. The cultured hepatocytes were treated with IL-1beta in the absence and presence of N(G)-monomethyl-L-arginine (L-NMMA) or L-arginine. Effects on nitric oxide production, ATP content, and ketone body ratio (KBR) were then compared between the CLP and sham groups. IL-1beta augmented the induction of NO production in hepatocytes from the CLP group compared with the sham group. IL-1beta markedly decreased cellular ATP content and KBR in the CLP group. The addition of L-arginine further enhanced the decreases of ATP content and KBR concomitantly with the increase of NO production in the CLP group. In contrast, L-NMMA, an inhibitor of nitric oxide synthase, abolished the effects of IL-1beta on ATP content and KBR, as well as on NO production. These results demonstrate that enhancement of NO production by IL-1beta stimulation is involved in cellular failure through mitochondrial dysfunction in the liver of septic rats. This experimental finding may explain clinical phenomenon that an initial insult primes the host so that the host's response is greatly amplified on a second or subsequent insult, resulting in the development of distant organ failure.     

Impact of combined C1 esterase inhibitor/coagulation factor XIII or N-acetylcysteine/tirilazad mesylate administration on leucocyte adherence and cytokine release in experimental endotoxaemia

We determined the effects of combinations of C1 esterase inhibitor (C1-INH) with factor XIII and of N-acetylcysteine (NAC) with tirilazad mesylate (TM) during lipo-polysaccharide (LPS)-induced endotoxaemia in rats. Forty Wistar rats were divided into four groups: the control (CON) group received no LPS; the LPS, C1-INH + factor XIII and NAC + TM groups received endotoxin infusions (5 mg/kg per h). After 30 min of endotoxaemia, 100 U/kg C1-INH + 50 U/kg factor XIII was administered to the C1-INH + factor XIII group, and 150 mg/kg NAC + 10 mg/kg TM was administered in the NAC + TM group. Administration of C1-INH + factor XIII and NAC + TM both resulted in reduced leucocyte adherence and reduced levels of interleukin-1beta (IL-1beta). The LPS-induced increase in IL-6 levels was amplified by both drug combinations. There was no significant effect on mesenteric plasma extravasation. In conclusion, the administration of C1-INH + factor XIII and NAC + TM reduced endothelial leucocyte adherence and IL-1beta plasma levels, but increased IL-6 levels.