Somatostatin inhibits pro-inflammatory cytokine secretion from rat hepatic stellate cells.

BACKGROUND/AIMS: Activated hepatic stellate cells (HSCs) have been implicated in hepatic fibrosis. Somatostatin (SOM) has an immunomodulatory role. The aim of this study was to assess the secretion of pro-inflammatory cytokines by HSCs and to determine the effect of SOM on the secretion of these mediators. METHODS: Activated rat HSCs were evaluated for their secretion of IL-1beta, IL-8, and TNF-alpha using ELISA. RNA protection assay was used to determine cytokine mRNA levels. The expression of chemokine and cytokine mRNA and the secretion of these mediators were assessed following incubation with SOM or octreotide. RESULTS: HSCs spontaneously secreted IL-1beta, IL-8, and TNF-alpha. This secretion was augmented following stimulation by IL-1beta and TNF-alpha. SOM inhibited the spontaneous and TNF-alpha-induced secretion of IL-1beta, IL-8, and TNF-alpha and suppressed the expression of IL-1beta and TNF-alpha mRNA. Octreotide suppressed the secretion of IL-1beta and IL-8. CONCLUSIONS: These observations indicate that SOM exerts an inhibitory immunomodulatory effect on HSCs.     

Dantrolene ameliorates the metabolic hallmarks of sepsis in rats and improves survival in a mouse model of endotoxemia.

Sepsis is the systemic inflammatory response resulting from serious infection and is the most common cause of death in intensive care units. Intracellular free calcium concentration ([Ca2+]i) is an important regulator of numerous cellular processes and when increased excessively may act as a potent cellular toxin. To determine if [Ca2+]i is responsible for the major metabolic changes which are hallmarks of sepsis, we examined if sodium dantrolene, a drug which decreases release of calcium from sarcoplasmic reticulum, affected the metabolic abnormalities in plasma and epitrochlearis muscles of rats made septic by cecal ligation and perforation. Dantrolene when added in vitro or when given in vivo decreases many of the metabolic hallmarks of sepsis--i.e., muscle protein breakdown approximately 30%, muscle glucose transport approximately 38%, muscle lactate formation approximately 28%, and plasma lactate approximately 29% (P < 0.05). In addition, we examined the ability of dantrolene to improve survival in a mouse model of endotoxemia. Dantrolene caused > 2-fold improvement in survival when it was administered concurrently with endotoxin (54% vs. 20% survival in dantrolene-treated and control mice, respectively (P < 0.001). Our results are consistent with the hypothesis that an increase in [Ca2+]i plays an important role in the metabolic abnormalities which occur during sepsis and that dantrolene administration may be an effective therapeutic strategy.     

乳果糖对肝癌切除术后血浆内毒素血症及肝损伤的防护作用

目的：探讨乳果糖对肝脏缺血再灌注后内毒素血症所致肝损伤的防护作用。方法：40例肝癌患者随机分为乳果糖组及对照组。测定两组肝癌手术患者肝门阻断前后门静脉血、外周静脉血内毒素以及术前、术后第1、3、7天肝功能检测结果,做统计学分析。结果：肝门阻断前,乳果糖组患者内毒素水平要低于对照组（t=27．60,P〈0．01）：肝门阻断后,两组患者内毒素水平均升高,但对照组更高,差异有极显著意义（t=12．72,P〈0．01）,说明乳果糖可以明显减轻内毒素血症。术前两组患者血中丙氨酸转氨酶（ALT）和天门冬氨酸转氨酶（AST）均高于正常参考值,但乳果糖组较对照组略低,差异有统计学意义（t=4．28,P〈0．01;t’=4．91,P〈0．05）,术后第3天两组患者ALT和AST升高的水平最高,两组问差异有统计学意义（t’=2．11,P〈0．05）。结论：肝切除术前患者口服乳果糖,能降低其肝缺血后血中内毒素水平,减轻肝脏的缺血再灌注损伤,改善肝脏功能,有利于术后肝功能的恢复,对于预防术后急性肝功能衰竭起一定作用。     

Anti-interleukin-4 treatment diminishes secretion of Th2 cytokines and inhibits hepatic fibrosis in murine schistosomiasis japonica

Anti-interleukin-4 (IL-4) treatment o/"Schistosoma japo-nicum-infected mice markedly inhibited in vitro secretion of the Th2 cytokines IL-4 and IL-5 from antigen-stimulated spleen cells, but enhanced the secretion of the Th1 cytokine IFN-γ. IL-2 secretion was unaffected. Hepatic fibrosis was markedly diminished in anti-IL-4-treated-mice at ten weeks of infection while granulomas around S. japonicum eggs in the livers were slightly-to-moderately increased in size. The number of eggs per worm pair in the tissues and feces did not differ significantly in treated and untreated mice. These findings suggest that Th2 cytokine responses are important in the genesis of schistosomal hepatic fibrosis.     

抗纤复方I号对乙醛刺激的肝星状细胞的细胞外基质及细胞因子分泌的干预作用

目的:研究乙醛对肝星状细胞(HSC) 细胞外基质和细胞因子分泌的影响及中药抗纤复方I号(KXI) 的干预作用.方法:采用大鼠肝脏原位灌流消化法获得并原代及传代培养HSC,大鼠灌以KXI 制备药物血清,以乙醛和药物血清作用于HSC,通过RTPCR 测定细胞内α1(I) 型胶原mRNA 的表达,以放射免疫法和ELISA 法...     

Vitamin E reduces chromosomal damage and inhibits hepatic tumor formation in a transgenic mouse model

We have previously shown that chronic activation of mitogenic signaling induced by over-expression of c-myc and transforming growth factor-alpha (TGFalpha) transgenes in mouse liver induces a state of oxidative stress. We therefore proposed that increased reactive oxygen species (ROS) generation might be responsible for the extensive chromosomal damage and acceleration of hepatocarcinogenesis characteristic for TGFalpha/c-myc mice. In this study, we show that vitamin E (VE), a potent free radical scavenging antioxidant, is able to protect liver tissue against oxidative stress and suppress tumorigenic potential of c-myc oncogene. Dietary supplementation with VE, starting from weaning, decreased ROS generation coincident with a marked inhibition of hepatocyte proliferation while increasing the chromosomal as well as mtDNA stability in the liver. Similarly, dietary VE reduced liver dysplasia and increased viability of hepatocytes. At 6 mo of age, VE treatment decreased the incidence of adenomas by 65% and prevented malignant conversion. These results indicate that ROS generated by over-expression of c-myc and TGFalpha in the liver are the primary carcinogenic agents in this animal model. Furthermore, the data demonstrate that dietary supplementation of VE can effectively inhibit liver cancer development.     

温阳解毒化瘀方对肝衰竭大鼠内毒素血症的影响

目的:动态观察温阳解毒化瘀方对肝衰竭大鼠内毒素血症(ITEM)的影响。方法:将85只SD大鼠随机分为正常组、模型组、对照组(予乳果糖+三联活菌溶液)及温阳解毒化瘀颗粒组(实验组),采用D-半乳糖胺(D-gal)腹腔注射致肝衰竭ITEM大鼠模型。正常组在腹腔注射生理盐水12小时后处死,其余各组分别于造模后12小时、24小时各取10只大鼠处死,检测各组大鼠血清转氨酶(ALT、AST)、肝组织病理学、门静脉及结肠内毒素水平。结果:模型组12小时时ALT和AST较正常组升高(P<0.05),24小时时门静脉及结肠内毒素水平明显升高(P<0.01),肝组织大面积坏死;实验组及对照组在造模后12小时各观察指标与模型组比较,差异无显著性意义,造模后24小时两组ALT和AST、门静脉及结肠内毒素水平较模型组降低(P<0.05),肝组织病变减轻。结论:D-gal腹腔注射可建立大鼠肝衰竭ITEM模型,温阳解毒化瘀方可通过降低门静脉及结肠内毒素水平减轻ITEM而达到抗肝衰竭的效应。     

Beneficial pleiotropic actions of melatonin in an experimental model of septic shock in mice: regulation of pro-/anti-inflammatory cytokine network, protection against oxidative damage and anti-apoptotic effects

Septic shock, the most severe problem of sepsis, is a lethal condition caused by the interaction of a pathogen-induced long chain of sequential intracellular events in immune cells, epithelium, endothelium, and the neuroendocrine system. The lethal effects of septic shock are associated with the production and release of numerous pro-inflammatory biochemical mediators including cytokines, nitric oxide and toxic oxygen and nitrogen radicals, together with development of massive apoptosis. As melatonin has remarkable properties as a cytokine modulator, antioxidant and anti-apoptotic agent, the present study was designed to evaluate the possible protective effect of melatonin against LPS-induced septic shock in Swiss mice. We observed that intraperitoneally (i.p.) administered-melatonin (10 mg/kg) 30 min prior, and 1 hr after i.p. LPS injection (0.75 mg/animal) markedly protected mice from the LPS lethal effects with 90% survival rates for melatonin and 20% for LPS-injected mice after 72 hr. The melatonin effect was mediated by modulating the release of pro-/anti-inflammatory cytokine levels, protection from oxidative damage and counteracting apoptotic cell death. Melatonin was able to partially counteract the increase in LPS-induced pro-inflammatory cytokine levels such as tumor necrosis factor-alpha, IL-12 and interferon-gamma at the local site of injection, while it increased the production of the anti-inflammatory cytokine IL-10 both locally and systemically. Furthermore, melatonin inhibited the LPS-induced nitrite/nitrate and lipid peroxidation levels in brain and liver and counteracted the sepsis-associated apoptotic process in spleen. In conclusion, we have demonstrated that melatonin improves the survival of mice with septic shock via its pleiotropic functions as an immunomodulator, antioxidant and anti-apoptotic mediator.     

The Ca2+-sensitizer levosimendan improves oxidative damage, BNP and pro-inflammatory cytokine levels in patients with advanced decompensated heart failure in comparison to dobutamine

AIM: To investigate the effect of a new inotropic drug, levosimendan compared with dobutamine on levels of brain natriuretic peptide (BNP), interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha), and malondialdehyde (MDA) in patients with severe decompensated heart failure. METHODS AND RESULTS: Twenty-nine consecutive patients (22 males and 7 females), mean age 70.5+/-9.9 years, with decompensated heart failure on standard medical therapy, were randomised to receive either a 24 h infusion of levosimendan (n=15) or dobutamine (n=14). Blood samples were drawn at baseline, 48 h and 5 days post infusion. Levosimendan produced a significant reduction in BNP compared to baseline, at both 48 h (744.1+/-100 vs 1136.3+/-93.7 pg/ml, p=0.04) and 5 days (446+/-119.3 vs 1136.3+/-93.7 pg/ml, p=0.03), while IL-6 values decreased after 5 days (4.8+/-1.3 vs 8.6+/-1.5 pg/ml, p=0.01). MDA levels were significantly lower 5 days after levosimendan compared to baseline (2.3+/-0.2 vs 3+/-0.3 microM, p=0.01). TNF-alpha levels did not differ between the groups. The comparison of percentage alteration compared to baseline showed that BNP (-44.5+/-7.6% vs 4.8+/-18.7%, p=0.025), MDA (-21.8+/-5.1% vs 14.9+/-8.5%, p=0.001) and IL-6 (-38.8+/-12.5% vs 70.2+/-24%, p=0.001) levels were significantly lower in the levosimendan group 5 days after treatment compared to the dobutamine group. CONCLUSIONS: Treatment with levosimendan in advanced decompensated heart failure exerts a beneficial hemodynamic, anti-inflammatory and antioxidant effect. These findings may give an insight into the favourable impact on mortality that levosimendan appears to have in published multicenter trials.     

Alteration of colony-stimulating factor output, endotoxemia, and granulopoiesis in cyclic neutropenia.

Cellular and humoral factors involved in the regulation of granulopoiesis were evaluated in two patients with cyclic neutropenia by utilizing the agar-gel marrow culture technique to serially study marrow granulocytic colony-forming capacity (CFC) and the urinary output of colony-stimulating factor (CSF). CSF output varied inversely with peripheral neutrophil counts and directly with monocyte counts and evidence for infection (endotoxemia and/or staphylococcal abscesses). Following autologous infusion of one patient's plasma obtained during a period of neutropenia, increased urinary excretion of CSF occurred concomitant with increments in both marrow CFC and the proportion of granulocytic progenitor cells in DNA synthesis. Neutrophil periodicity was not altered by the administration of the neutropenic plasma. These findings are consistent with the hypothesis that cyclic neutropenia is caused by a quantitatively decreased entry of stem cells or granulocytic progenitor cells into granulopoiesis.