血小板激活因子在烧伤合并内毒素血症早期肠粘膜损害中的作用

目的：探讨血小板激活因子（ＰＡＦ）在烧伤合并内毒素内毒素粘膜损害中的作用。方法：采用２０％Ⅲ度体表烧伤合并小剂理内毒素（ＬＰＳ １ｍｇ／ｋｇ）注射的大鼠模型,动态检测了肠组织ＰＡＦ,磷脂酶Ａ２（ＰＬＡ２）,黄嘌呤氧化酶（ＸＯ）,丙二醛（ＭＤＡ）等的变化。     

血小板活化因子拮抗剂对急性出血坏死型胰腺炎大鼠内毒素血症的防治作用

目的：观察血小板活化因子（ＰＡＦ）拮抗剂对急性出血坏死型胰腺炎（ＡＨＮＰ）大鼠内毒素血症的防治作用。方法：１４０只ＳＤ大鼠随机分为３组：急性胰腺炎组（ＡＰ组）：采用去氧胆酸钠逆行胰管内注射法复制；治疗组（ＢＮ组）：制备模型后经腹腔注射ＰＡＦ特异性受体拮抗剂ＢＮ５２０２１（５ｍｇ／ｋｇ）；假手术组（ＳＯ组）：开腹后仅轻轻翻动胰腺即关腹。结果：ＢＮ组与ＡＰ组比较，１小时后血清淀粉酶值明显下降〔（１４９７０±２５００）Ｕ／Ｌ，（１６１７０±２３８０）Ｕ／Ｌ，Ｐ＜０．０５〕，６小时和１２小时后更为明显（Ｐ均＜０．０１）；血中ＰＡＦ含量１小时后明显降低〔（２．２０±０．２５）μｇ／Ｌ与（１．１０±０．２１）μｇ／Ｌ，Ｐ＜０．０５〕，３小时后更为明显（Ｐ＜０．０１）。血浆内毒素含量ＢＮ组比ＡＰ组明显下降（Ｐ＜０．０１）。ＢＮ组术后大鼠平均存活时间为（４５．０±２５．１）小时，存活率为４０％；ＡＰ组术后大鼠在２４小时内全部死亡，平均存活时间为（１１．５±４．８）小时，存活率为０（Ｐ均＜０．０１）。结论：ＰＡＦ参与了ＡＨＮＰ的发病过程；应用ＰＡＦ受体拮抗剂对实验性ＡＨＮＰ有良好的防治作用。     

血小板第4因子及四肽AcSDKP的造血保护作用研究

目的了解血小板第４因子（ＰＦ４）和四肽Ｎ乙酰丝天赖脯（ＡｃＳＤＫＰ）对５氟尿嘧啶（５ＦＵ）处理后小鼠体内造血的作用。方法实验鼠用ＰＦ４（４０μｇ／ｋｇ）或ＡｃＳＤＫＰ（４μｇ／ｋｇ）注射２次,间隔６小时,第２次注射后２０小时再注射５ＦＵ（１５０ｍｇ／ｋｇ）。第６,８和１３天时,检查高增殖潜能的集落形成细胞（ＨＰＰＣＦＣ）、红系爆式集落形成单位（ＢＦＵＥ）、粒巨噬系集落形成单位（ＣＦＵＧＭ）、巨核系集落形成单位（ＣＦＵＭＫ）及巨核细胞（ＭＫ）。结果ＰＦ４或ＡｃＳＤＫＰ可促使６～８天的ＨＰＰＣＦＣ以及８天的ＢＦＵＥ和ＣＦＵＧＭ明显增加;ＰＦ４还能促进８天的ＣＦＵＭＫ和ＭＫ增加,但ＡｃＳＤＫＰ则无此作用。结论ＰＦ４和ＡｃＳＤＫＰ虽然对巨核祖细胞的作用不同,但它们均能加速体内ＨＰＰＣＦＣ、ＣＦＵＧＭ和ＢＦＵＥ的恢复,这两种分子有可能具有保护造血细胞抵抗化疗药物杀伤的作用。     

血小板活化因子拮抗剂对急性出血坏死型胰腺炎大鼠内毒…

目的：观察血小板活化因子（ＰＡＦ）拮抗剂对急性出血坏死型胰腺炎（ＡＨＮＰ）大鼠内毒素血症的防治作用。方法：１４０只ＳＤ大鼠随机分为３组：急性胰腺炎组（ＡＰ组）：采用去氧胆酸钠逆行胰管内注射法复制；治疗组（ＢＮ组）：制备模型后经腹腔注射ＰＡＦ特异性受体拮抗剂ＢＮ５２０２１（５ｍｇ／ｋｇ）；假手术组（ＳＯ组）：开腹后仅轻轻翻动胰腺即关腹。结果：ＢＮ组与ＡＰ组比较，１小时后血清淀粉酶值明显下降〔（１４９     

胰岛素治疗高血压动脉硬化性脑梗死的实验研究

目的：观察胰岛素（ Ｉｎｓ）对高血压动脉硬化大鼠脑梗死的疗效。方法：５０ 只肾血管性高血压大鼠（ Ｒ Ｈ Ｒ）复制成大脑中动脉闭塞（ Ｍ Ｃ Ａｏ）模型,随机分４ 组： Ａ 组１２ 只（ Ｉｎｓ ２１ Ｕ／ｋｇ）, Ｂ组１２ 只〔 Ｉｎｓ ２１ Ｕ／ｋｇ＋ ５０％ 葡萄糖（２ ｇ／ｋｇ）〕, Ｃ组 １２ 只〔 Ｉｎｓ ４５ Ｕ／ｋｇ＋ ５０％ 葡萄糖（４ ｇ／ｋｇ）〕和 Ｄ组 １４ 只（生理盐水 ４ ｍ ｌ／ｋｇ）。各组均于 Ｍ Ｃ Ａｏ 后即注射胰岛素, Ｍ Ｃ Ａｏ 后 ４ 小时和２４ 小时检查神经功能,２４ 小时处死大鼠取脑,测大脑体积和梗死灶体积。结果： Ａ 组的血糖较其他组有统计学意义的下降（ Ｐ均＜ ００１）, Ｃ组的神经功能障碍评级、梗死灶体积及其与大脑体积的百分比的减少都有统计学意义（ Ｐ 均＜ ００１）, Ａ、 Ｂ、 Ｄ组间比较则无差异（ Ｐ 均＞００５）。结论：胰岛素对缺血脑组织具有不依赖于其降糖作用的直接保护作用, Ｒ Ｈ Ｒ Ｍ Ｃ Ａｏ 后注射胰岛素在较高剂量时才显示疗效,这可能与高血压致脑血管发生病变有关。     

脂多糖诱导大鼠肝脏中两类磷脂酶A2激活及基因表达

目的：观察脂多糖（ＬＰＳ）在大鼠肝脏中诱导磷脂酶Ａ２（ＰＬＡ２）亚型的激活和基因表达情况。方法：大鼠腹腔注射脂多糖（ＬＰＳ．２ｍｇ／ｋｇ）后不同时间取血,分别测定分泌型ＰＬＡ２（ｓＰＬＡ２）活笥和前列腺素Ｅ２（ＰＧＥ２）含量,用Ｗｅｓｔｅｒｎ ｂｌｏｔ检测肝脏中胞浆型ＰＬＡ２（ｃＰＬＡ２）蛋白的表达和时间进程;采用免疫组化法检测ｓＰＬＡ２和ｃＰＬＡ２蛋白在肝脏中的表达;用ｍＲＮＡ斑点杂交法检测ｓＰ     

钠氢交换体及其抑制物在急性肺损伤中的作用

目的 探讨钠氢交换体及其抑制物在急性肺损伤中的作用。方法 应用内毒素（ＬＰＳ,５ｍｇ／ｋｇ）复制大鼠急性肺损伤模型。将２１只ＳＤ大鼠随机分成三组：正常对照组（ＮＳ组）;内毒素组（ＬＰＳ组）;ＬＰＳ＋ＤＭＡ组（Ｌ＆Ｄ组）,该组以钠氢交换体抑制体ＤＭＡ（５ｍｇ／ｋｇ）预处理。大鼠均于５小时后处死,然后测定各组的肺系数（ＬＩ）及血浆和支气管肺泡灌洗液（ＢＡＬＦ）中的ＴＮＦ、ＥＴ－１、ＮＯ的浓度变化。结果     

己酮可可碱对内毒素休克犬的影响

目的 研究己酮可可碱（ＰＴＸ）在内毒素休克时所起的作用。方法 选用成年杂种犬１２只,随机分成２组,第一组（ｎ＝６）按２５０μｇ／ｋｇ持续静注内毒素３０ｍｉｎ,第二组（ｎ＝６）除用同样的方法静注内毒素外,在静注内毒素前按２０ｍｇ／ｋｇ静推ＰＴＸ后按２０ｍｇ．ｋｇ＾－１．ｈ＾－１持续静注ＰＴＸ。两组动物从开始到结束持续静注生理盐水维持ＣＶＰ及ＰＣＷＰ在基础水平。每隔半小时测量一次ＭＡＰ、ＭＰＡＰ、ＣＶ     

大黄对大鼠肠缺血再灌注所致肺损伤过程肿瘤坏死因子、一氧化氮和磷脂酶A2的影响

目的：观察肿瘤坏死因子（ＴＮＦ）、内源性一氧化氮（ＮＯ）和磷脂酶Ａ２（ＰＬＡ２）在大鼠小肠缺血再灌注（ＩＲ）所致肺损伤发病过程中的作用,及大黄对ＴＮＦ、ＮＯ和ＰＬＡ２的影响,探讨大黄防治肠源性肺损伤的机制。方法：ＳＤ大鼠随机分为肠缺血再灌注组、假手术组、大黄治疗组和安慰剂组。以１２５Ｉ标记小牛血清白蛋白（ＢＳＡ）肺摄取指数作为评价肺损伤的指标,以髓过氧化物酶（ＭＰＯ）作为评价多形核白细胞（ＰＭＮ）在组织中聚集的指标,分别测定各组动物不同时间血浆、肺组织ＴＮＦ含量,血浆（血清）、肺及小肠组织内源性ＮＯ含量及ＰＬＡ２活性。结果：大黄可显著改善ＩＲ导致的低血压状态并明显抑制再灌注导致的肺ＭＰＯ活性升高（Ｐ＜０．０１）;抑制肠缺血和再灌注早期出现的血浆及肺组织ＴＮＦ水平升高（Ｐ＜０．０１）;抑制肠缺血期和再灌注期血清、肺及小肠组织ＰＬＡ２活性升高（Ｐ＜０．０５或Ｐ＜０．０１）及再灌注期的内源性ＮＯ释放（Ｐ＜０．０５或Ｐ＜０．０１）;降低肺毛细血管通透性（Ｐ＜０．０１）。结论：缺血再灌注早期应用大黄能明显防治大鼠ＩＲ所致的肺损伤,这种作用可能是通过抑制ＴＮＦ、内源性ＮＯ及ＰＬＡ２等介质的释放实现的。     

内毒素血症对左室心肌血液灌流和血液分配的影响

目的：观察内毒素血症对左室心肌血液灌流和血液分布的影响。方法：２８只家兔随机分成４组,每组７只（对照组、内毒素组、抗体保护组和无关抗体组）。后３组静注内毒素（０．１ｍｇ／ｋｇ）,对照组注射等量生理盐水。内毒素注射前３０分钟抗体保护组和无关抗体组各静注相应抗肿瘤坏死因子（ＴＮＦ）单克隆抗体（５ｍｌ／ｋｇ）和抗白介素－２（ＩＬ－２）单克隆抗体（５ｍｌ／ｋｇ）。使用放射性生物微球技术测量左室心肌血液灌流     

Effects of MCI-154, a calcium sensitizer, on cardiac dysfunction in endotoxic shock in rabbits

This study was designed to observe the effects of MCI-154, a calcium sensitizer, on cardiac dysfunction after endotoxic shock in rabbits. Ten hours after the rabbits were given injection of 1.0 mg/kg endotoxin (Escherichia coli, O111:B4) via marginal ear veins, 0.1 mg/kg MCI-154 was injected intravenously and then 50 mL/kg normal saline (NS) + 0.1 mg/kg MCI-154 was infused continuously at a rate of 0.7 mL/min. During this process, the parameters of cardiac function were measured. It was found that 10 h after the endotoxin injection, heart rate (HR) was increased significantly while the mean arterial blood pressure (MAP), left ventricular systolic pressure (LVSP), isovolumetric pressure (IP), myocardial contractility (MC), and the area of p-dp/dt(max) vector loop (Lo) all were markedly decreased. Treatment with 50 mL/kg NS alone had slight effects on these parameters. On the contrary, LVSP, IP, MC, and Lo all were increased significantly while HR was not obviously changed and left ventricular end-diastolic pressure (LVEDP) was reduced remarkably following MCI-154 administration in endotoxic shock rabbits. The parameters of myocardial contractility were improved nearly to the values in sham shock group and were markedly higher than that in NS alone-treated group. It can be concluded that MCI-154 can exert significant therapeutic effects on cardiac dysfunction after endotoxic shock, for it improves cardiac function, dilates peripheral blood vessels, and slightly affects HR.     

连续性静-静脉血液滤过对内毒素休克羊血流动力学的影响

目的　探讨连续性静静脉血液滤过( CVVH)对内毒素休克血流动力学的影响及作用机制,并观察其对内毒素休克预后的影响。方法　利用大肠杆菌内毒素( L 2 880 )诱导绵羊内毒素休克模型,随机分为对照组( NHF)和治疗组( HF)两组,观察CVVH(零平衡,40 ml·kg-1·h-1超滤,血流速80 ml/ min)对内毒素休克羊血流动力学的影响。结果　内毒素注入后两组实验动物平均动脉压( MAP)明显下降;平均肺动脉压( MPAP)、心脏指数( CI)显著升高( P<0 .0 1或P<0 .0 5)。实施CVVH后,HF组MAP、每搏量( SV)明显上升,显著高于NHF组( P<0 .0 1或P<0 .0 5) ;HF组CI无明显变化,NHF组进行性下降并显著低于HF组( P<0 .0 5) ;两组MPAP差异无显著性( P>0 .0 5) ;血浆乳酸浓度NHF组明显高于HF组。5h后HF组全部存活,NHF组死亡2只。结论　应用大肠杆菌内毒素静脉注射可成功制备羊内毒素休克模型;CVVH具有改善内毒素休克血流动力学和预后的作用,是治疗内毒素休克的重要手段。     

“717复方”制剂对内毒素损伤大鼠肝细胞线粒体的保护作用

目的：观察“７１７复方”制剂对内毒素休克大鼠肝细胞线粒体的保护作用。方法：采用静脉注射内毒素制备大鼠内毒素休克模型，观察“７１７复方”对休克大鼠肝细胞线粒体功能的影响。结果：模型组大鼠肝细胞线粒体呼吸控制率（ＲＣＲ）明显下降，与正常对照组比较（４．５８±０．３１比５．７３±０．３５）有显著性差异（Ｐ＜０．０５）；电镜下，内毒素休克模型线粒体明显肿胀，嵴减少、模糊不清。“７１７复方”制剂组大鼠肝细胞线粒体ＲＣＲ（５．６８±０．４１）则接近正常，与模型组比较有极显著性差异（Ｐ＜０．０１）；其电镜下超微结构病变也较轻。体外实验测定肝细胞线粒体膜通透性（膜吸光度下降百分比），“７１７复方”制剂组明显低于内毒素组（Ｐ＜０．０１）。结论：“７１７复方”制剂具有拮抗内毒素损伤线粒体的作用     

Oxygen Free Radicals and Endotoxic Shock: Effect of Flaxseed

BACKGROUND: Cardiac dysfunction and tissue injury during endotoxemia may be caused by increased levels of oxygen free radicals. METHODS AND RESULTS: We therefore investigated the effects of endotoxic shock on cardiac function and contractility, plasma creatine kinase (CK) activity and lactate concentration, oxyradical-producing activity of polymorphonuclear leukocytes (PMNL-CL) and white blood corpuscles, antioxidant reserve (cardiac chemiluminescence [LV-CL]), antioxidant enzyme activity (superoxide dismutase, catalase, glutathione peroxidase), cardiac malondialdehyde (MDA) concentration, a lipid peroxidation product, and hemodynamics in the absence or presence of flaxseed treatment in anesthetized dogs. Flaxseed contains lignans that have antioxidant activites and inhibit platelet-activating factor (PAF). The dogs were assigned to three groups: group I, sham control; group II, endotoxin (ET) treated (5 mg/kg intravenously); group III, ET + flaxseed (2 gm/kg/day orally) for 6 days. ET produced a decrease in cardiac function and contractility and antioxidant enzyme levels, and an increase in cardiac MDA and LV-CL, PMNL-CL, and plasma CK and lactate. Pretreatment with flaxseed attenuated the ET-induced cardiac dysfunction and cellular damage. Protection was incomplete for cardiovascular function, plasma CK, and lactate. CONCLUSIONS: These results suggest that oxyradicals and/or PAF may be involved in the deterioration of cardiovascular function and cellular integrity during ET shock and that antioxidant and anti-PAF agents may be effective in the treatment of ET shock.     

Endotoxic shock alters the pharmacokinetics of lidocaine and monoethylglycinexylidide

Significant hepatic dysfunction occurs following endotoxin administration. Although the metabolism of lidocaine to one of the primary metabolites of lidocaine, monoethylglycinexylidide (MEGX), has been used as a marker of hepatic function under various conditions, it remains unknown whether these compounds can be used in vivo to evaluate hepatic function in a rat model of endotoxic shock. To study this, cytochrome P450-3A4 (CYP3A4) was determined after harvesting hepatic microsomes, hepatic blood flow was determined using radioactive microspheres, and the pharmacokinetics of lidocaine and MEGX were evaluated. Adult male Sprague-Dawley rats were divided into endotoxin (45 mg/kg, intraperitoneally; n = 28) or control (n = 32) groups. The CYP3A4 was significantly reduced after endotoxic shock. Carboxylesterase (hydrolase S) content, which was used as a control for microsomal protein, was not significantly different between groups. Total hepatic blood flow was significantly decreased (36.2 +/- 8.4 mL/min/100 g tissue vs. 120.4 +/- 10.6 mL/min/100 g tissue), which was due to the decreased portal blood flow. For the lidocaine and MEGX experiment, lidocaine (2 mg/kg) was administered followed by serial blood samples collected up to 2 h for determination of serum lidocaine and MEGX concentrations. Mean arterial pressure (MAP) was recorded throughout the experiment. The MAP was significantly lower in the endotoxin treated rats vs. control 7.5 to 8 h following endotoxin administration. Serum concentrations of lidocaine were higher in endotoxic shock versus control animals at 2 h following lidocaine administration (1.5 +/- 0.13 mg/L vs. 0.11 +/- 0.03 mg/L). Similarly, MEGX concentrations were significantly higher in endotoxic shock versus control animals (0.55 +/- 0.04 mg/L vs. 0.16 +/- 0.02, respectively) under such conditions. These data demonstrate that the elimination of lidocaine and MEGX is impaired during endotoxic shock. The elevated lidocaine and MEGX concentrations are likely to be the result of primarily reduced hepatic blood flow and secondarily due to impaired CYP450, one of which was CYP3A4. The reduced elimination of MEGX concentrations is not due to decreased hepatic metabolism of the compound via carboxylesterase. The ratio of MEGX to lidocaine concentrations, which decreased significantly following endotoxic shock, appears to be a useful measure of hepatic function during endotoxic shock where profound reductions of hepatic blood flow are observed in addition to significant reductions in CYP450. The use of only MEGX concentrations in this endotoxic shock model is not useful in evaluating liver function.     

大黄对大鼠肠缺血再灌注所致肺损伤的作用

背景:肠道因素尤其是肠缺血再灌注可导致远隔器官损伤是创伤。中药大黄能通过清除氧自由基,促进肠粘膜内杯状细胞增生,抑制肠道内细菌过度繁殖和肠道内毒素吸收及活血化瘀、改善微循环等途径发挥良好的肠黏膜屏障保护作用,进而可能发挥防治肺损伤的作用。目的:观察大黄对肠缺血-再灌注所致肺损伤的防治效应,以及对肿瘤坏死因子和磷脂酶A2的影响。设计:随机对照观察。单位:解放军兰州军区乌鲁木齐总医院急诊科。材料:实验于2003-02/07在解放军第二军医大学完成。选取SD大鼠80只,随机分为肠缺血再灌注组24只,假手术组16只,治疗组24只,生理盐水组16只四组。方法:肠缺血-再灌注组,术前禁食,麻醉,然后经腹正中切口,分离肠系膜上动脉,无创血管夹夹闭之,缝合切口;45min后取出动物夹,恢复血供。治疗组造模同肠缺血再灌注组,恢复血供前30min经胃管灌入精黄片600mg/kg混悬液,。生理盐水组造模同肠缺血再灌注组,于恢复血供前30min经胃管灌入等量的生理盐水。假手术组除不夹闭肠系膜上动脉外,其余手术过程均同肠缺血-再灌注组。以病理学改变及125Ⅰ标记牛血清白蛋白肺摄取指数作为评价肺损伤的指标,分别测定各组动物不同时间肺组织TNF含量及血清、肺及小肠组织PLA2活性。主要观察指标:观察125Ⅰ标记牛血清白蛋白肺摄取指数,血浆、肺组织肿瘤坏死因子含量,血清、肺及小肠组织磷脂酶A2活性。结果:①肺组织病理形态学变化:假手术组未见明显异常;肠缺血再灌注组6h后肺间质出现水肿,并有中性粒细胞浸润,可见肺泡水肿,有少量出血及纤维蛋白渗出。治疗组仅见轻度肺间质水肿及少量中性粒细胞。②肺组织超微病理变化:假手术组未见明显变化。肠缺血再灌注组6h后,可见肺毛细血管内皮细胞肿胀,中性粒细胞向肺间质及肺泡腔渗出。治疗组无上述变化。③肺组织肿瘤坏死因子变化:假手术组和治疗组(再灌注组30min)明显低于肠缺血再灌注组(再灌注30min)(0.235±0.114,1.374±0.550,16.315±4.587,P<0.01)。④125Ⅰ-BSA肺摄取指数:治疗组明显低于肠缺血-再灌注组和生理盐水组(P<0.01),与假手术组差异无显著性(P>0.05)。结论:早期应用大黄有助于防治肠源性肺损伤的发生。进而发挥组织病程向多器官功能不全综合征发展的重要作用,这种作用可能是通过抑制TNF和PLA2等介质的释放实现的。     

Oxygen radicals in experimental shock: effects of spin-trapping nitrones in ameliorating shock pathophysiology.

BACKGROUND: Circulatory shock is accepted as a consequence of an acute oxygen radical overgeneration. Spin-trapping nitrones inactivate free radicals by forming relatively stable adducts. OBJECTIVE: Three spin-trapping nitrones (N-tert-phenyl-butyl-nitrone; alpha-4-pyridyl-oxide-N-tert-butyl-nitrone; 5-5,dimethyl,1,pyrroline-N-oxide) were tested regarding their role in the pathophysiology and evolution of circulatory shock in rats. DESIGN: Prospective, randomized, controlled trial of spin-trapping nitrones in rats experiencing three different models of circulatory shock. EXPERIMENTS AND RESULTS: In the first group, endotoxic, traumatic, and mesenteric artery occlusion shock (all 100% lethal in control experiments) was prevented by the ip administration of N-tert-phenyl-butyl-nitrone (150 mg/kg); alpha-4-pyridyl-oxide-N-tert-butyl-nitrone (100 mg/kg); or 5-5,dimethyl,1,pyrroline-N-oxide (100 mg/kg). However, the evolution of shock was unaffected by the same compounds when all three nitrones had been previously inactivated by exposure to light and air. In the second group, microcirculatory derangements that were provoked by endotoxin and were observed in the mesocecum of rats were completely prevented by pretreatment with either peritoneal administration of each of the three nitrones or by their topical application to the microscopic field. While the rats survived after systemic treatment, those rats receiving topical nitrones died from endotoxic shock. In the third group, cell-membrane stiffness (a sign of peroxidative damage) was measured by spin-probes and electron-spin resonance in mitochondrial and microsomal membranes. Cell membranes obtained from shocked rats were more rigid than those membranes of controls. However, the membranes obtained from rats that were submitted to trauma or endotoxin after pretreatment with N-tert-phenyl-butyl-nitrone had normal stiffness. The fourth group of experiments was carried out to quantify ethane (one of the final products of lipid peroxidation) in the exhaled air of shocked rats. Ethane concentrations increased in direct proportion to the worsening of the condition. Pretreatment of the rats with N-tert-phenyl-butyl-nitrone prevented such an increase. CONCLUSIONS: Since nitrones are effective inactivators of oxygen-radicals, or of their secondary radicals, these data confirm the relationship between oxygen-radicals and experimental shock. The therapeutic use of spin-trapping nitrones should possibly be considered for future use in shock.     

L-canavanine, a selective inhibitor of inducible NO synthase, increases plasma endothelin-1 concentrations in dogs with endotoxic shock

PURPOSE: The purpose of this article is to elucidate the effect of L-canavanine, a selective inhibitor of inducible NO synthase (iNOS), on hemodynamics, blood gas parameters, and plasma concentrations of lactate and endothelin-1 (ET-1) during endotoxic shock. MATERIALS AND METHODS: Eleven mongrel dogs under pentobarbital anesthesia were divided into two groups: (1) bacterial lipopolysaccharide (LPS) plus vehicle group (n = 5) receiving infusion of LPS (3 mg/kg/h for 1 h) followed by vehicle (2 mL/h for 5 hours); (2) LPS plus L-canavanine group (n = 6) receiving infusion of LPS (3 mg/kg/h for 1 hour) followed by L-canavanine (10 mg/kg/h for 5 hours). RESULTS: LPS caused a significant (P < .05) decrease in mean arterial pressure (MAP) at 1 hour, but there was no significant difference in MAP during 6-hour period between the two groups. LPS alone did not cause significant changes in other hemodynamics, whereas L-canavanine caused a significant (P < .05) increase in pulmonary vascular resistance index (PVRI) and a decrease in oxygen delivery at 6 hours.The LPS-induced lactic acidosis and hypersecretion of ET-1 were aggravated after L-canavanine infusion. Plasma ET-1 showed positive correlations to lactate levels and PVRI, and negative correlations to cardiac output and oxygen delivery only in the LPS plus L-canavanine group, but not in the LPS plus vehicle group. CONCLUSIONS: This study suggests that L-canavanine induces tissue hypoperfusion and ischemia with concomitant hypersecretion of ET-1 in dogs with endotoxic shock.     

正常淋巴液对内毒素休克大鼠肺组织髓过氧化物酶活性及膜泵的作用研究

目的观察外源性正常淋巴液对脂多糖（LPS）所致内毒素休克大鼠肺组织匀浆髓过氧化物酶（MPO）活性及肺组织细胞膜泵功能的作用，探讨其干预机制。方法雄性Wistar大鼠40只，按随机数字表法均分为内毒素组、淋巴液组、血浆组和对照组。除对照组外，其他各组应用LPS5mg／kg复制内毒素休克模型，对照组以等量生理盐水代替LPS；15min后，淋巴液组自颈静脉输入仅占全血量1／15的无细胞淋巴液；血浆组以血浆代替淋巴液；内毒素组和对照组以生理盐水代替淋巴液。给予LPS（或相应液体）后4h，制备体积分数为10％的肺组织匀浆，检测肺组织匀浆MPO及膜ATP酶的活性。结果与对照组相比，内毒素组和血浆组大鼠肺组织匀浆MPO活性显著增高、4种膜ATP酶活性均显著下降（P＜0．05或P＜0．01）。淋巴液组肺组织匀浆MPO活性显著高于对照组，Na^＋-K^--ATP酶活性显著低于对照组，两组比较差异均有显著性（P均＜0．05）；而Ca^2＋-ATP酶、Mg^2＋-ATP酶和Ca^2＋-Mg^2＋-ATP酶活性与对照组比较差异均无显著性（P均＞0．05）；淋巴液组肺组织匀浆MPO活性显著低于内毒素组及血浆组（P均＜0．01），4种膜ATP酶活性显著高于内毒素组及血浆组（P＜0．05或P＜0．01）。结论外源性正常淋巴液对内毒素休克所致的肺损伤具有干预作用，其机制可能与减少中性粒细胞激活、提升膜ATP酶活性有关。     

血浆血小板激活因子与急性肺损伤相关性及"神农33"注射液对其影响的观察

目的：探讨内毒素（ＬＰＳ）诱导急性肺损伤（ＡＬＩ）时血小板激活因子（ＰＡＦ）含量变化情况及“神农３３”注射液对ＰＡＦ及ＡＬＩ的影响。方法：给Ｗｉｓｔａｒ大鼠静脉注射ＬＰＳ,制成ＡＬＩ模型;采用反相高效液相色谱法检测ＬＰＳ攻击后１小时大鼠血浆ＰＡＦ含量,观察ＬＰＳ攻击后３小时大鼠肺湿、干重,光镜观察大鼠肺病理形态学变化。结果：ＡＬＩ组动物的肺湿重、湿干重比、肺含水量均明显高于正常对照组（Ｐ均＜０．０５）,肺病理组织学改变明显且严重。ＡＬＩ组大鼠血浆ＰＡＦ含量明显高于正常对照组（Ｐ＜０．０１）,单独给予“神农３３”注射液无明显降低ＰＡＦ的作用（Ｐ＞０．０５）,而以“神农３３”注射液保护的大鼠ＰＡＦ含量明显低于ＡＬＩ组,同时肺损伤也较轻。结论：ＰＡＦ在ＬＰＳ诱导的ＡＬＩ中起重要作用,“神农３３”注射液有拮抗ＰＡＦ及保护肺脏的作用