双环醇对四环素诱发小鼠急性脂肪肝的保护作用

研究双环醇对四环素诱发小鼠急性脂肪肝的影响。小鼠一次腹腔注射四环素(180 mg·kg^-1) 24 h后，收集血样和肝组织，采用生化法测定肝脏甘油三酯(triglyceride，TG)、胆固醇(cholesterol，CHO)、谷胱甘肽(glutathione，GSH)含量，以及血清脂质和转氨酶水平；光谱法测定小鼠线粒体脂肪酸β-氧化速率以及肝脏极低密度脂蛋白(very low density lipoprotein，VLDL，TG)分泌速率。结果表明，双环醇(150及300 mg·kg^-1)连续灌胃给药3次可以不同程度地保护四环素引起的小鼠肝脏TG和CHO升高以及血清谷丙转氨酶(alanine aminotransferase，ALT)、谷草转氨酶(aspartate aminotransferase，AST)升高和脂质异常。双环醇(300 mg·kg^-1)还可减轻四环素诱发小鼠肝脏丙二醛(malondialdehyde，MDA)生成增加和GSH水平降低，并能抑制肝线粒体脂肪酸β-氧化速率下降。双环醇(300 mg·kg^-1)可部分逆转四环素所致小鼠肝脏VLDL(TG)分泌速率的减少。由此可见，双环醇对四环素诱发小鼠急性脂肪肝具有明显的保护作用，其作用机制与保护肝线粒体β-氧化功能、改善肝脂蛋白分泌及转运以及抑制肝脏脂质过氧化密切相关。     

鲨肝活性肽对对乙酰氨基酚致小鼠急性肝损伤的保护作用

目的探讨鲨肝活性肽(sHSS)对对乙酰氨基酚(AAP)致小鼠急性肝损伤的保护作用。方法用AAP(200 mg·kg^-1,ip)诱导小鼠急性肝损伤,用改良赖氏法测血清ALT和AST,通过光镜和电镜观察肝细胞显微和亚显微结构的变化,用流式细胞仪分析肝细胞凋亡,同时用RT-PCR方法分析Fas mRNA表达水平。结果sHSS 3.0和1.5 mg·kg^-1可显著降低肝损伤小鼠血清ALT和AST的水平;改善模型鼠肝组织细胞坏死及炎症反应;高剂量sHSS(3 mg·kg^-1)对肝线粒体具有保护作用,下调Fas mRNA的表达水平,并具有抗凋亡作用。结论sHSS对AAP诱导的肝损伤具有明显的保护作用,其机制可能与保护肝线粒体、抑制Fas基因表达及肝细胞凋亡有关。     

双环醇对对乙酰氨基酚致小鼠肝线粒体损伤的保护作用

目的观察双环醇对对乙酰氨基酚(acetaminophen,AP)引起小鼠肝脏线粒体损伤的保护作用.方法用AP诱发小鼠肝及肝线粒体损伤,测定血清转氨酶和观察肝形态病理学改变,判定双环醇对AP诱发肝损伤的保护作用;测定肝线粒体中谷草转氨酶(AST)和谷胱甘肽(GSH)的含量、肝线粒体膜的肿胀和流动性以及观察超微结构的变化,评定双环醇对线粒体损伤的保护作用.结果双环醇50,150mg@kg-1灌胃能保护AP引起的小鼠肝损伤,使血清转氨酶(ALT和AST)水平显著降低,肝脏形态的病理损伤减轻,防止肝线粒体中AST和GSH的降低以及肝线粒体超微结构的损伤,使线粒体膜的流动性以及肝线粒体对外加Ca2+引发肿胀的敏感性恢复正常.体外加药也能直接防止Ca2+及TritonX-100引发的线粒体膜肿胀.结论双环醇对AP引起的小鼠肝线粒体损伤具有明显的保护作用.     

双环醇对刀豆蛋白A引起肝损伤小鼠肝脏基因表达谱的影响

本实验研究双环醇对刀豆蛋白A(concanavalin A，Con A)静脉注射引起免疫性肝损伤小鼠肝脏基因表达谱变化的影响，探讨双环醇肝保护作用的分子机制。小鼠于注射Con A 26.5 mg·kg^-1前24、 8及1 h分别口服双环醇250 mg·kg^-1。测定血清丙氨酸转氨酶(alanine aminotransferase，ALT)及天冬氨酸转氨酶(aspartate aminotransferase，AST)水平，提取小鼠肝脏总RNA，经反转录用Cy3-dUTP和Cy5-dUTP分别标记制备cDNA探针。将cDNA探针与BiostarM-40S小鼠基因表达谱芯片进行杂交，经ScanArray 4000扫描仪扫描芯片并用GenePix Pro 3.0软件进行分析。双环醇可显著抑制刀豆蛋白A引起的血清ALT和AST升高。与刀豆蛋白A对照组相比，双环醇给药组有287条基因发生差异表达，占芯片基因总数的7.00%。其中166条基因表达量明显下调，121条基因表达量明显上调。表达变化的基因主要涉及代谢与细胞色素P450、应激与炎症凋亡、细胞周期调控、信号传导以及再生等相关功能。双环醇对刀豆蛋白A引起小鼠肝损伤肝脏基因表达谱变化具有一定的影响，此结果对今后深入研究双环醇的肝脏保护作用特点和临床应用具有重要意义。     

阿魏酸钠部分减轻氢化泼尼松引起的小鼠肝脏毒性

氢化泼尼松(Pred)20mg·kg^-1可明显增高小鼠sGPT与sGST水平,增加肝匀浆MDA含量及肝微粒体与线粒体膜流动性。表明Pred致sGPT及sGST水平增高与肝脂质过氧化作用增强及膜流动性改变有关。经1g阿魏酸钠(SF)100mg·kg^-1使sGPT与sGST水平降低,肝脏MDA含量减少,但sGPT与MDA仍高于正常对照组水平。肝微粒体膜流动性恢复,线粒体膜流动性进一步增高。电镜观察亦见线粒体仍有损害,提示SF不能完全对抗Pred所致肝损害。     

联苯双酯对他克林引起的肝损伤的保护作用

目的　观察联苯双酯(DDB)对他克林(THA)诱发小鼠肝损伤的保护作用。方法　小鼠一次poTHA(56mg·kg^-1) ,观察12h内动物血清ALT ,肝脏MDA和动物体温的改变;分光光度法测定小鼠脑乙酰胆碱酯酶活性;酶动力法测定小鼠肝微粒体7-乙氧基香豆素脱乙基酶和UDP葡糖醛酸转移酶(UDPGT)的活性;荧光法测定线粒体膜电位的改变。结果　DDB 200 mg·kg^-1 可明显保护THA引起的小鼠体温下降、血清ALT和肝脏MDA的升高。DDB(100 μmol·L^-1 )可减轻THA造成的大鼠线粒体膜电位降低。DDB还可提高小鼠肝微粒体7-乙氧基香豆素脱乙基酶的活性,但对UDPGT无影响。结论　DDB似通过降低肝脏脂质过氧化反应、提高线粒体膜稳定性、调节THA代谢酶活性发挥其肝保护作用     

脑5-HT1A/1B、α2受体及腺苷酸环化酶参与了胍丁胺的抗抑郁作用

为了在单胺受体及受体后腺苷酸环化酶(adenylate cyclase,AC)水平探讨胍丁胺(agmatine,AGM)抗抑郁作用的精细机制,采用小鼠悬尾实验和强迫游泳实验观察AGM抗抑郁行为改变。采用放射免疫方法测定大鼠前额皮层突触膜蛋白AC活性。结果表明,AGM(5～40 mg·kg^-1,ig)在小鼠悬尾实验和强迫游泳实验模型上均有显著抗抑郁活性。同时伍用β受体/5-HT_1A/1B受体阻断剂吲哚洛尔(pindolol, PIN, 20 mg·kg^-1, ip)、 α₂肾上腺素受体拮抗剂育亨宾(yohimbine, YOH, 5～10 mg·kg^-1, ip)或咪唑克生(idazoxan, IDA, 4 mg·kg^-1, ip)对AGM(40 mg·kg^-1, ig)的抗抑郁活性具有显著拮抗效应; 而β受体阻断剂普萘洛尔(propranolol, PRO, 5～20 mg·kg^-1, ip)或5-HT₃受体拮抗剂曲匹西隆(tropisetron, TRO, 5～40 mg·kg^-1, ip)对AGM(40 mg·kg^-1, ig)的抗抑郁活性无显著影响。AGM(0.1～6.4 μmol·L^-1)与大鼠前额皮层提取的突触膜共孵可剂量依赖地激活AC活性, 而PIN(1 μmol·L^-1)或YOH(0.25～1 μmol·L^-1)均显著拮抗AGM(6.4 μmol·L^-1)对AC的激活作用; 慢性给予大鼠AGM(10 mg·kg^-1, ig, bid)或氟西汀(fluoxetine, FLU, 10 mg·kg^-1, ig, bid) 2 w也显著增强大鼠前额皮层基础及Gpp(NH)p 预激活的AC活性。本研究表明, 调节脑内5-HT_1A/1B和α₂等受体功能, 并激活前额皮层AC可能是AGM抗抑郁活性的重要机制之一。     

映山红花总黄酮对盐酸异丙肾上腺素诱导大鼠心肌缺血的保护作用

目的观察映山红花总黄酮(TFR)对盐酸异丙肾上腺素诱导的实验性心肌缺血的保护作用。方法采用皮下(sc)注射盐酸异丙肾上腺素(Iso)(8 mg·kg^-1×2 d)诱导大鼠实验性心肌缺血模型,测定血清中MDA含量、GSH-PX活力、SOD及心肌组织中ATPase活性。同时行心肌组织病理组织学检查。结果TFR 30 mg·kg^-1显著降低血清中MDA的生成,30,15 mg·kg^-1及60,30 mg·kg^-1升高SOD,GSH-PX的活力,60,30 mg·kg^-1TFR可抑制心肌组织中Na⁺-K⁺-ATPase,Ca²⁺-Mg²⁺-AT-Pase,总ATPase活力的降低,TFR 60,30 mg·kg^-1能显著改善sc Iso后心肌病理损伤程度,降低其病理损伤评分。结论TFR对盐酸异丙肾上腺素诱导的实验性心肌缺血有保护作用,其机制可能与减少体内自由基生成、改善心肌能量代谢有关。     

苦参碱联合甘草甜素在四氯化碳慢性肝损伤中的保护作用及机制

摘 要 目的：考察苦参碱联合甘草甜素在四氯化碳（CCl₄）慢性肝损伤中的保护作用,并从能量代谢及CYP酶的角度探讨其保护机制。方法: 建立CCl₄慢性肝损伤模型,通过考察血清ALT、AST观察两药及其联合用药在慢性肝损伤模型中的保护作用;检测血清谷氨酸脱氢酶（GLDH）及肝组织中肝脏腺嘌呤核苷三磷酸（ATP）、二磷酸腺苷（ADP）、腺嘌呤核糖核苷酸（AMP）含量,评价药物对肝脏能量代谢及线粒体功能的调节作用;实时定量PCR及Western Blot法检测肝脏CYP1A2、CYP2E1 mRNA及蛋白水平,评价两药及其联合用药对肝脏CYP酶的调控作用。结果: 苦参碱（72.8 mg·kg^-1）、甘草甜素（43.4 mg·kg^-1）在CCl₄慢性肝损伤模型中均可降低大鼠血清ALT、AST（P<0.05）,两药联合（36.4 mg·kg^-1 苦参碱+21.7 mg·kg^-1 甘草甜素）使用保护作用更加显著(P<0.05);其中苦参碱（72.8 mg·kg^-1）、甘草甜素（43.4 mg·kg^-1）均可降低血清GLDH,并恢复肝脏ATP含量(P<0.05);苦参碱（72.8 mg·kg^-1）对CYP1A2、CYP2E1mRNA表达水平无抑制作用,甘草甜素（43.4 mg·kg^-1）对CYP1A2、CYP2E1mRNA及蛋白表达水平均有抑制作用（P<0.05）。结论: 苦参碱联合甘草甜素在慢性肝损伤模型中具有明显的线粒功能调节和肝保护作用。     

解酒饮保护小鼠急性酒精性肝损伤的研究

目的 探讨解酒饮对小鼠急性酒精性肝损伤的保护作用。方法 将小鼠随机分为正常对照组、联苯双酯组（11.7 mg·kg^-1）、模型对照组和解酒饮低、中、高剂量（6.25,12.5,25 g·kg^-1）组6组,每组10只,每天1次,连续14 d灌服给药。末次给药后1 h,除正常对照组外按12 ml·kg^-1剂量一次性灌胃给予56°北京红星二锅头造模。12 h后处死小鼠取血标本和肝组织标本,比较各组的肝脏指数,并对肝组织进行组织形态学检查,测定血清谷丙转氨酶（ALT）、谷草转氨酶（AST）的活性水平。结果 解酒饮可显著降低酒精诱导的急性肝损伤小鼠的血清ALT、AST水平,可减少肝中脂肪空泡,减轻炎症表现,急性肝损伤肝脏指数明显改善。结论 解酒饮对小鼠急性酒精性肝损伤有一定的保护作用。     

Thymoquinone supplementation reverses acetaminophen-induced oxidative stress,nitric oxide production and energy decline in mice liver

This study was undertaken to evaluate the protective effect of thymoquinone (TQ) against acetaminophen-induced hepatotoxicity. Mice were given TQ orally at three different doses (0.5, 1 and 2 mg/kg/day) for 5 days before a single hepatotoxic dose of acetaminophen (500 mg/kg i.p.). TQ supplementation dramatically reduced acetaminophen-induced hepatotoxicity, in a dose-dependent manner, as evidenced by decreased serum alanine aminotransferase (ALT) activities.Acetaminophen (500 mg/kg i.p.) resulted in a significant increase in serum ALT and total nitrate/nitrite, hepatic lipid peroxides and a significant decrease in hepatic reduced glutathione (GSH) and ATP in a time-dependent manner. Interestingly, supplementation of TQ (2 mg/kg/day) for 5 days before acetaminophen administration resulted in reversal of acetaminophen-induced increase in ALT, total nitrate/nitrite, lipid peroxide and a decrease in GSH and ATP. Moreover, TQ did not affect acetaminophen-induced early decrease in hepatic GSH indicating lack of the effect on the metabolic activation of acetaminophen.In conclusion, TQ is effective in protecting mice against acetaminophen-induced hepatotoxicity possibly via increased resistance to oxidative and nitrosative stress as well as its ability to improve the mitochondrial energy production.     

Anti-hepatotoxic effects of 3,4-methylenedioxyphenol and N-acetylcysteine in acutely acetaminophen-overdosed mice

3,4-Methylenedioxyphenol (sesamol) is effective against acetaminophen-induced liver injury in rats. Whether sesamol's anti-hepatotoxic effect is comparable to that of N-acetylcysteine has never been studied. We investigated the anti-hepatotoxic effects of sesamol and N-acetylcysteine on acetaminophen-induced hepatotoxicity in mice. Equimolar doses (1 mmol/kg) of sesamol and N-acetylcysteine significantly inhibited acetaminophen (300 mg/kg)-increased serum aspartate transaminase and alanine transaminase levels 6 h post-administration. Sesamol and N-acetylcysteine maintained hepatic glutathione levels and inhibited lipid peroxidation. Moreover, the combination of sesamol and N-acetylcysteine antagonistically inhibited sesamol's protection against acetaminophen-induced liver injury. We conclude that the protective effect of sesamol against acetaminophen-induced liver damage is comparable to that of N-acetylcysteine by maintaining glutathione levels and inhibiting lipid peroxidation in mice.     

双环醇通过抑制线粒体凋亡途径缓解TNF-α/D-GalN诱导的爆发性肝损伤

目的探讨双环醇对肿瘤坏死因子-α/D-半乳糖胺(TNF-α/D-GalN)诱导肝损伤的保护作用及可能机制。方法雄性C57小鼠灌胃给予双环醇50、100及200 mg·kg-1·d-1,连续5 d,末次给药2 h后,腹腔注射TNF-α及D-GalN建立爆发性肝炎模型。观察小鼠生存率,评价血清ALT、AST水平,肝组织病理损伤及细胞凋亡情况。Western blot方法检测肝组织Bax、Bcl-2和激活型caspase-3/-9蛋白表达水平。根据离体线粒体膜通透性转换孔(mPTP)开放程度及线粒体细胞色素C的胞质释放情况评价双环醇抗凋亡效应与线粒体保护作用的相关性。结果双环醇明显提高TNF-α/D-GalN所致肝损伤小鼠的生存率,降低血清ALT、AST水平,减轻肝组织病理损伤和肝细胞凋亡。机制研究显示双环醇降低Bax并升高抗凋亡蛋白Bcl-2水平,减轻TNF-α/D-GalN诱导的线粒体mPTP开放及细胞色素C的胞质释放,进而抑制caspase-3/-9的活性及蛋白激活水平。结论双环醇对TNF-α/D-GalN诱导的爆发性肝损伤具有明显的保护作用,其机制与减轻线粒体损伤,进而抑制线粒体凋亡途径有关。     

双环醇对大鼠肾脏缺血-再灌注损伤的保护作用

目的观察双环醇对缺血-再灌注诱发肾损伤的保护作用.方法在大鼠肾动脉缺血-再灌注模型上观察双环醇对肾缺血-再灌注引起的血清丙二醛(MDA)、尿素氮(BUN),肾脏还原型谷胱甘肽(GSH)、谷胱甘肽巯基转移酶(GST)及肾线粒体膜流动性改变的影响.结果双环醇ig 50及200 mg*kg-1可剂量依赖性保护缺血-再灌注引起的血清MDA及BUN升高、肾GSH含量降低,同时可诱导GST活性,缓解由于缺血-再灌注损伤引起的线粒体膜流动性降低.结论双环醇对肾缺血-再灌注损伤有保护作用.     

Dioscin, a natural steroid saponin, shows remarkable protective effect against acetaminophen-induced liver damage in vitro and in vivo

The aim of the study was to investigate the protective effect of dioscin against APAP-induced hepatotoxicity. In the in vitro tests, HepG2 cells were given APAP pretreatment with or without dioscin. In the in vivo experiments, mice were orally administrated dioscin for five days and then given APAP. Some biochemical and morphology parameters were assayed and the possible mechanism was investigated. Dioscin improved AST release, mitochondrial dysfunction, apoptosis and necrosis of HepG2 cells induced by APAP. Following administration of dioscin, APAP-induced hepatotoxicity in mice was significantly attenuated. Furthermore, the liver cell apoptosis and necrosis, and hepatic mitochondrial edema were also prevented. Fifteen differentially expressed proteins were found by using proteomics, and six of them, Suox, Krt18, Rgn, Prdx1, MDH and PNP were validated. These proteins may be involved in the hepatoprotective effect of dioscin and might cooperate with the levels of Ca(2+) in mitochondria, decreased expression of ATP2A2, and decreased mitochondrial cardiolipin. In addition, dioscin inhibited APAP-induced activation and expression of CYP2E1, up-regulated the expression of Bcl-2 and Bid, and inhibited the expression of Bax, Bak and p53. Dioscin showed a remarkable protective effect against APAP-induced hepatotoxicity by adjusting mitochondrial function. These results indicated that dioscin has the capability on the treatment of liver injury.     

Effect of acetaminophen hepatotoxicity on hepatic mitochondrial and microsomal calcium contents in mice

The effect of toxic doses of acetaminophen on hepatic intracellular calcium compartmentation were studied in mice. No effects on the calcium contents of the mitochondria, microsomes or cytosol were observed 4 h after the administration of 175 and 375 mg/kg acetaminophen when compared to saline-treated controls. However, doses of 500 and 750 mg/kg of acetaminophen increased mitochondrial calcium contents at this time. Also, the 750 mg/kg dose caused marked alterations in the calcium contents of microsomal and cytosolic compartments. The time-course of the onset of these effects was examined using a 500 mg/kg dose. No changes in either mitochondrial, microsomal or cytosolic calcium contents were observed in the livers of mice treated with acetaminophen compared to saline-treated controls at either 1 or 2 h after dose administration. However, at 3, 4 and 24 h after acetaminophen, mitochondrial and cytosolic calcium contents were significantly increased above control values. The increases in mitochondrial and cytosolic calcium contents observed in the acetaminophen-intoxicated mouse liver appear to occur at the same time as the appearance of plasma membrane damage, as measured by sorbitol dehydrogenase leakage. The data suggest that a perturbation in hepatic calcium compartmentation is not an early event in acetaminophen-induced hepatotoxicity in the mouse.     

Studies on the effects of l-ascorbic acid on acetaminophen-induced hepatotoxicity: 1. Inhibition of the covalent binding of acetaminophen metabolites to hepatic microsomes in vitro

The covalent binding of [¹⁴C]acetaminophen metabolites to male mouse hepatic microsomes was inhibited by the sulfhydryl compounds, reduced glutathione, cysteamine, and l-cysteine, and also by l-ascorbic acid (vitamin C, LAA). Although the sulfhydryl compounds were more effective inhibitors of macromolecular binding than LAA, the combination of LAA with any of the thiol agents resulted in additive inhibition of covalent binding of [¹⁴C]acetaminophen metabolites. Similar results were obtained in studies with hepatic microsomes from female mice and male hamsters. Investigations into the mechanism of inhibition of covalent binding of [¹⁴C]acetaminophen metabolites indicated that LAA probably acts by scavenging the reactive intermediates generated by the microsomal mixed-function oxidase enzymes rather than by the inhibition of their formation. The results suggest that LAA, at concentrations found in rodent and human liver, may supplement the endogenous protective mechanisms (such as reduced glutathione) which operate in vivo to prevent the covalent binding of reactive acetaminophen metabolites and hence hepatic necrosis. The possible application of this study to the use of LAA in the prevention and treatment of acetaminophen-induced hepatotoxicity in man is discussed.     

Protective role of dietary butylated hydroxyanisole against chemical-induced acute liver damage in mice

Prior consumption of a diet containing the food antioxidant, butylated hydroxyanisole (BHA), by female mice prevented the development of or minimized the acute liver damage caused by monocrotaline, acetaminophen, or bromobenzene. In contrast, neither the incidence nor the severity of carbon tetrachloride-induced hepatotoxicity was affected by dietary BHA. Hepatotoxicity was judged by plasma alanine aminotransferase and aspartate aminotransferase levels, hepatic cytochrome P-450 content, and liver histology. The protective effect of BHA against acetaminophen-induced hepatotoxicity was not demonstrated in male mice. The observed protection by dietary BHA against acetaminophen- and bromobenzene-induced hepatotoxicity was associated with the increase of liver glutathione. It is concluded that the protective action of BHA is dependent upon the nature of the toxic agent.     

Effects and mechanisms of rifampin on hepatotoxicity of acetaminophen in mice

This study examined the effects and possible mechanisms of rifampin against acetaminophen-induced hepatotoxicity in mice. Rifampin significantly enhanced the biotransformation of acetaminophen, evidenced by the increase in p-aminophenol formation in rifampin-treated microsomes and the increase in plasma clearance rate of acetaminophen. Pretreatment with rifampin significantly decreased serum alanine transaminase (ALT) activities, aspartate transaminase (AST) activities and prevented severe liver necrosis following acetaminophen overdose. The contents and activities of microsomal drug-metabolizing enzyme were less affected in rifampin-pretreated mice in comparison to the animals treated with acetaminophen alone. Rifampin was capable of increasing glutathione (GSH) level and GSH reductase activity and reducing GSH depletion and the decrease in GSH reductase activity by acetaminophen in mice. In addition, it was found that the microsomal Ca²⁺-ATPase activity was not directly related to acetaminophen toxic species generated in the P450 enzyme system in vitro. These findings suggest that rifampin has species-specific effects on the liver against acetaminophen-induced hepatotoxicity in mice, which increase the level of GSH by promoting GSH regeneration.     

Failure of exogenous prostaglandin to afford complete protection against acetaminophen-induced hepatotoxicity in the rat

The protective effect of 16, 16-dimethylprostaglandin E2 (dm-PGE2) against acetaminophen-induced hepatotoxicity was determined in the rat. The dm-PGE2 was administered at two dose levels both before and after acetaminophen administration. The hepatotoxicity was evaluated by a rise in serum transaminases 24 h after acetaminophen administration and by histological examination of liver preparations. The urinary acetaminophen and its metabolites were determined by high-pressure liquid chromatography. The results suggest that exogenous dm-PGE2 administration had a modest protection against acetaminophen-induced hepatotoxicity, in contrast to its well established cytoprotective effect against many noxious agents in the gastrointestinal tract. Prostaglandin treatment had little effect on acetaminophen metabolites excretion in the urine, suggesting that it did not affect the cytochrome P-450-dependent mixed-function oxidase drug-metabolizing enzyme system. The livers from dm-PGE2-acetaminophen-treated rats showed less advanced necrosis compared to those from saline-acetaminophen-treated rats. Whereas only 2 of 13 rats died in the prostaglandin-treated group, 4 of 13 rats died in the saline-treated group.