老年大鼠内毒素血症时心肌血红素氧合酶1和一氧化碳系统变化分析

目的探讨内毒素血症时老年大鼠心肌血红素氧合酶1(HO-1)和CO系统的变化。方法 39只SD大鼠分为老年对照组7只、青年对照组12只、老年内毒素组8只、青年内毒素组12只。采用尾静脉注射脂多糖(3 mg/kg)制备内毒素模型,4 h后取血及心脏,检测血浆CO水平;光镜及电镜观察心肌病理改变;免疫组织化学法检测心肌HO-1的表达。结果与老年对照组和青年对照组比较,老年内毒素组和青年内毒素组CO水平明显升高(P<0.05);与老年内毒素组比较,青年内毒素组CO水平明显降低(P<0.05)。注射脂多糖后,老年和青年内毒素组大鼠均出现心肌细胞变性,间质毛细血管轻度扩张充血等病变,但老年组较青年组更严重。与青年内毒素组比较,老年内毒素组HO-1 A值明显升高(P<0.05)。结论内毒素血症时,老年大鼠心肌更容易受到损伤。HO-1/CO系统在老年内毒素组的表达更加明显,可能与其心肌细胞内蛋白变性严重、存在更加强烈的氧化应激有关。     

Age-related differences in the response of the brain to dietary melatonin

The aged brain is prone to excessive levels of immune activity, not initiated by an acute response to an extrinsic agent. While dietary melatonin is reported to attenuate the extent of expression of proinflammatory genes, little is known about the extent to which these changes can be translated into altered levels of corresponding proteins. The baseline levels of the proinflammatory cytokines, tumor necrosis factor alpha (TNF-α) and interleukin-1 alpha, were greater in older (~29 months old) compared to younger (~7 months old) mouse brains. Acute (3 h) exposure to lipopolysaccharide (LPS) induced activation of nuclear factor kappa B (NF-κB), but not inflammatory cytokines in the brain. The serum level of TNF-α was increased after LPS injection, indicating a systemic immune response to the bacterial cell wall component. Dietary melatonin (40 ppm for 9.3 weeks) did not prevent LPS-induced changes in younger animals but caused an increased systemic TNF-α response in older mice. Melatonin did reduce markers of carbonyl formation in brain proteins of young animals and nitrosylative damage to peptide-bound amino acid residues, in the brains of older animals. Acute LPS challenge did not significantly affect these oxidative markers. Thus, despite lack of clear evidence of attenuation of the NF-κB–cytokine inflammatory trajectory within the CNS by melatonin, this agent did show a protective effect against free radical-initiated injury to amino acid residues within proteins. The results illustrate that previously reported changes in gene expression following melatonin treatment need not be closely paralleled by corresponding changes in protein content.     

Alteration of myocardial antioxidant enzyme activity and glutathione content with aging and exercise training

Antioxidant enzyme activities and glutathione (GSH) content were investigated in the ventricular myocardia of adult (4.5 mo.), mid-age (14.5 mo.), and old (26.5 mo.) male Fischer 344 rats. In addition, the effect of 10 wks of exercise training (T) on these antioxidant systems was evaluated at each age. T was performed on a rodent treadmill for 1 hr/day, 5 days/wk at a speed and grade adjusted for the animal’s age. Activities of superoxide dismutase (SOD), glutathione peroxidase (GPX), and glutathione disulfide (GSSG) reductase were increased by 39%, 27% and 38%, respectively (p<0.05), in old vs young rats. T has no significant effect on antioxidant enzyme activities at any age. Myocardial protein concentration of the aged heart was significantly lower compared to that of the adult or young rats. Total glutathione concentration in the heart was increased in old (12.5±0.6) vs adult (10.7±1.2) and mid-age (9.7±0.9 nmol/mg protein) rats (p<0.05), however the GSH/GSSG ratio was not altered by T in any age group. Myocardial malondialdehyde (MDA) content was increased (p<0.001)with aging. However, MDA content in mid-age and old T rats was decreased by 21 and 25%, respectively, compared to their untrained counterparts (p<0.05). It is concluded that aged hearts are susceptible to oxidative stress despited increased antioxidant capacity and that training may attenuate the age-associated increase in lipid peroxidation in the heart.     

Lipo prostaglandin E1 reduces the production of CXC chemokines in endotoxin-induced rat liver injury

The present study attempted to assess the effect of prostaglandin E1 (PGE1) incorporated into lipid microspheres (Lipo PGE1) on chemokine production in endotoxin-induced rat liver injury. Male Wistar rats weighing 200–250 g were injected with 2 mg lipopolysaccharide (LPS) per kg intravenously. Lipo PGE1 was administered simultaneously at various concentrations (0.002, 0.02, 0.2, 2 μg/kg) in the tail vein. Blood samples and liver specimens were taken from the rats at 1, 3, 8, 12 and 24 h after injection with LPS alone or with LPS and Lipo PGE1. Serum macrophage inflammatory protein-2 (MIP-2) and cytokine-induced neutrophil chemoattractant (CINC) levels were measured by the enzyme-linked immunosorbant assay using the corresponding antibodies. Liver specimens were fixed, and the number of neutrophils that had infiltrated each liver section was determined under a microscope. Serum alanine aminotransferase (ALT) levels were significantly lower in the rats injected with LPS and Lipo PGE1 compared with those in the rats injected with LPS alone, and this difference was expressed in a PGE1 dose-dependent manner. Serum MIP-2 levels were significantly lower at 3 h (141.4±95.5 pg/ml) and 8 h (44.9±44.7 pg/ml) after injection with LPS and Lipo-PGE1 (2 μg/kg) than at the same times after injection with LPS alone (342.9±35.9 and 358.3±23.4 pg/ml, respectively). Similarly, serum CINC levels were significantly lower at 8 h (482.7±156.0 ng/ml) after injection with LPS and Lipo-PGE1 (2 μg/kg) than at the same time after injection LPS alone (723.3±29.0 ng/ml). No significant differences were observed at any time between serum tumor necrosis factor-α (TNF-α) levels in rats injected with LPS alone and in rats injected with LPS and Lipo-PGE1 (2 μg/kg). The number of neutrophils that had infiltrated the liver was significantly lower at 8 h after injection with LPS and Lipo PGE1 than at the same time after injection with LPS alone. This difference was expressed in a Lipo PGE1 dose-dependent manner. In conclusion, Lipo PGE1 reduces liver injury and serum levels of MIP-2 and CINC, but not TNF-α, in rats injected with LPS and also reduces the number of neutrophils that infiltrate in the liver.     

脂多糖对多巴胺能神经元的损毁作用

目的离体、在体水平分别观察脂多糖（LPS）对多巴胺（DA）能神经元的毁损作用，及其对动物行为的影响。方法将LPS、6-羟基多巴胺（6-OHDA）和LPS与小胶质细胞共培养的上清液分别加入大鼠嗜铬细胞瘤（PC12）细胞中，四唑盐比色试验（MTT）观察一定时间内细胞活性的变化；将LPS注入大鼠单侧黑质，在一定时间内，观察动物行为的变化；免疫组化法检测黑质区DA能神经元数目，高压液相色谱（HPLC）洲定黑质纹状体系统DA等及其代谢产物含量。结果LPS对PCI2细胞活性无直接影响，LPS与小胶质细胞共培养组和60HDA组则对PC12细胞活性有明显影响，使细胞活性分别下降26％和30％；大鼠单侧黑质注入LPS后21、28d，阿朴吗啡诱发大鼠出现旋转行为，转次为4～6次／min；注射侧黑质TH阳性细胞数减少约35％～60％，尤以21、28d明显；LPS注射后14、21d和28d大鼠的纹状体和黑质DA及其代谢物含量降低30％～70％。结论LPS间接地对DA能神经元产生一定的损毁作用，并可导致大鼠偏侧旋转行为的发生。     

Age-dependent lipopolysaccharide-induced iNOS expression and multiorgan failure in rats: effects of melatonin treatment

Senescence amplifies the sensitivity to endotoxemia, which correlates with increased nitric oxide (NO) levels and mortality. Melatonin displays antioxidant and anti-inflammatory effects, but its levels decrease with age. Lipopolysaccharide (LPS) (10 mg/kg) was injected to 3- and 18-month-old rats 6 h before they were killed, and melatonin (60 mg/kg) was injected before and/or after LPS. Inducible nitric oxide synthase (iNOS) expression and activity, nitrite content, lipoperoxidation (LPO) levels, and serum markers of liver, renal, and metabolic dysfunction, were measured in liver and lung of these animals. An age-dependent increase in iNOS activity, NO content, and LPO levels was observed, and these changes were augmented further by LPS. Melatonin decreased the expression and activity of iNOS, reducing NO and LPO levels to basal values in both septic LPS-treated groups. Liver, kidney, and metabolic dysfunctions were also significantly higher in aged that in young rats and further increased by LPS. Melatonin treatment counteracted these alterations in young and aged septic rats. Melatonin reduced LPS-dependent iNOS expression and multiorgan failure in a similar extent in young and aged rats. Because aged rats showed higher organ and metabolic impairment than young animals in response to LPS, the results also suggest an increased efficacy of the anti-septic properties of melatonin in the aged animals.     

The effect of chronic intraperitoneal infusion of bacterial endotoxin on exocrine pancreas function in rats

Summary Conclusion This study demonstrated that LPS infusion can induce tissue lesions and impair the exocrine protein secretion of the pancreas in rats. Background The effect of chronic ip infusion of lipopolysaccharide (LPS) on the exocrine pancreas function was studied in rats. Methods Four milligrams per kilogram per day ofSalmonella typhi LPS were infused intraperitoneally by means of surgically implanted osmotic pumps. Rats were studied after 7-d LPS infusion. Results Plasma fibrinogen and amylase activity increased significantly in LPS-treated rats when compared with control rats. Histological examination of the pancreas showed congestion, infiltration, and focal necrosis in LPS-treated rats. The pancreas wet weight, as well as DNA and total soluble protein contents were significantly increased in LPS-treated animals when compared with controls. The pancreas protein output was significantly decreased in pure pancreatic juice, whereas the pancreatic juice flow rate was significantly increased in LPS-treated animals, when compared with controls. Electrophoretic patterns showed a marked decrease in digestive enzyme contents, whereas there was an increased content of 15 kDa protein.     

Lipopolysaccharide treatment reduces rat platelet aggregation independent of intracellular reactive-oxygen species generation

High production of reactive-oxygen species (ROS) by blood cells is involved in damage of the vascular endothelium and multiple organ dysfunction in sepsis. However, little is known about the intraplatelet ROS production in sepsis and its consequences on platelet reactivity. In this study, we evaluated whether the treatment of rats with lipopolysaccharide (LPS) affects platelet aggregation through intraplatelet ROS generation. Rats were injected with LPS (1?mg/kg, i.p.), and at 2 to 72?h thereafter, adenosine diphosphate (ADP) (3–10?µM) induced platelet aggregation was evaluated. Production of ROS in platelets was measured by flow cytometry using 2′,7′-dichlorofluorescein diacetate (DCFH-DA). Treatment of rats with LPS time-dependently inhibited ADP-induced platelet aggregation within 72?h. The inhibitory effect of LPS on platelet aggregation was further increased when the platelets were incubated with polyethylene glycol-superoxide dismutase (PEG-SOD; 30?U/mL), polyethylene glycol-catalase (PEG-CAT; 1000?U/mL) or the NADPH oxidase inhibitor diphenyleneiodonium (DPI; 10?µM). The ROS production in non-stimulated platelets did not differ between control and LPS-treated rats. However, in ADP-activated platelets, generation of ROS was increased by 3.0- and 7.0-fold, as evaluated at 8 and 48?h after LPS injection, respectively. This increased ROS production was significantly reduced when platelets were incubated in vitro with DPI, PEG-SOD or PEG-CAT. In contrast, treatment of rats with N-acetylcysteine (150?mg/kg, i.p.) significantly reduced the inhibitory effect of LPS on platelet aggregation, and prevented the increased ROS production by in vivo LPS. Our results indicate that the increased intraplatelet ROS production does not contribute to the inhibitory effect of LPS on platelet aggregation; however, the maintenance of redox balance in LPS-treated rats is fundamental to restore the normal platelet response in these animals.     

Changes in activity of µ- and m-calpains and signs of neuroinflammation in the hippocampus and striatum of rats after single intraperitoneal injection of subseptic dose of endotoxin

Some mechanisms of neuronal degeneration in endotoxinemia are already well described, but need to be detailed. In this study, we tested the effect of a single intraperitoneal injection of a LPS sub-septic dose (1 mg/kg of animal weight) on calpain activity in the striatum and hippocampus. We showed, that in the hippocampus the day after LPS administration an increase in production of IL-1β and TNF-α mRNA, followed by elevated mRNA expression and activity of µ- and m-calpains without signs of microglia activation is observed. In striatal cells, the day after LPS injection an increase in expression of IL-1β, TNF-α, IBA-1, m-calpain and calpastatin mRNA is revealed, which only intensifies over time. The elicited changes are accompanied by a decrease in motor behavior, which can be considered as a sign of sickness behavior. In the hippocampus, 180 days after LPS administration expression of TNF-α, content and activity of µ-calpain are increased. In the striatum, elevation in expression of TNF-α, IBA-1, µ- and m-calpain mRNA, with hyperactivation of only m-calpain, is observed. Significantly reduced motor activity can be a consequence of LPS-induced neuronal death. A long-lasting endotoxin activates microglia that damage neurons via proinflammation cytokines and calpain hyperactivation. The endotoxin hypothesis of neurodegeneration is unproven, but if correct, then neurodegeneration may be reduced by decreasing endotoxin-induced neuroinflammation and m-calpain hyperactivation. Therefore, the drugs, that decrease endotoxin-induced neuroinflammation and differently inhibit µ- or m-calpain, can be used to prevent or reduce the severity of neurodegeneration.

     

Nitric Oxide and Liver Injury in Alcohol-Fed Rats after Lipopolysaccharide Administration

Earlier studies showed that alcohol-fed animals were more susceptible than controls to injurious effects of endotoxin. Increased super-oxide radical production by hepatocyte organelles, Kupffer cells, and neutrophils from alcohol-fed animals has been well documented. In this study, electron paramagnetic resonance spectroscopy was used to detect nitrosyl protein complexes indicating nitric oxide (˙NO) production. We showed that the concentrations of nitrosyl complexes in whole blood and in liver tissues of alcohol-fed rats treated with lipopolysaccharide (alc+LPS), increased 3-fold, compared with those from rats on control diet treated with LPS (con+LPS). Electron paramagnetic resonance spectra of whole blood and liver tissues from the alc+LPS-treated group exhibited features characteristic of hemoglobin nitrosyl complexes. Plasma levels of the hepatic ASTs and ALTs from the alc+LPS-treated group were increased 2- to 3-fold, compared with those from the con+LPS-treated group. Inhibition of ˙NO production by aminoguanidine treatment attenuated plasma hepatic enzyme levels in the alc+LPS-treated group. Thus, under the conditions of elevated inflammatory oxidative states caused by chronic alcohol feeding, endotoxin treatment enhanced liver injury as a result of the actions of ˙NO, and/or the cytotoxic species derived from ˙NO.     

Comparison of PDE 4 inhibitors, rolipram and SB 207499 (ariflo), in a rat model of pulmonary neutrophilia

Using a rat model of lipopolysaccharide (LPS)-induced pulmonary inflammation, the antiinflammatory activity of SB 207499 was evaluated and compared to that of the prototypic type-4 phosphodiesterase (PDE4) inhibitor, rolipram. In dose-response experiments, we found that rats exposed to 10 microg or 100 microg of intratracheal (it) LPS developed a prominent pulmonary inflammation, due to a significant increase in the number of recoverable bronchoalveolar lavage neutrophils. The pulmonary neutrophilia, provoked by the challenge of 10 microg LPS/rat, was significant at 2 h, peaked by 16 h, declined thereafter but remained elevated for up to 48 h. Additionally, the exposure of rats to 10 microg LPS caused the local pulmonary production of TNF- alpha. In contrast to the cellular influx, TNF- alpha production peaked at 2 h and rapidly declined to negligible levels by 8 h. While low levels were detected, the levels of IL-1 beta in bronchoalveolar lavage did not significantly differ from saline challenged animals. Rats pretreated with rolipram or SB 207499, displayed dose-dependent inhibition of the LPS-induced pulmonary inflammation. Nevertheless, the pulmonary production of TNF- alpha and IL-1 beta was unaffected by either SB 207499 or rolipram. When provoked with the 10 microg dose of LPS, adrenalectomized rats produced a similar 24 h induction of pulmonary neutrophilia. Pretreatment of adrenalectomized rats with the PDE4 inhibitors showed similar inhibitory results to those obtained in normal rats. In summary, we have shown, using a rat model of LPS-induced pulmonary neutrophilic inflammation, that the inhibitory activities of rolipram or SB207499 are not linked to the production of TNF- alpha or the inhibition of IL-1 beta, and occur independently of endogenous catecholamine or corticosteroid release. Copyright Academic Press.     

Magnolol attenuates sepsis-induced gastrointestinal dysmotility in rats by modulating inflammatory mediators

AIM： To investigate the protective effects of magnolol on sepsis-induced inflammation and intestinal dysmotility. METHODS： Sepsis was induced by a single intraperitoneal injection of lipopolysaccharide （LPS）. Male Wistar rats were randomly assigned to one of three treatment groups： magnolol prior to LPS injection （LPS/Mag group）; vehicle prior to LPS injection （LPS/Veh group）; vehicle prior to injection of saline （Control/Veh）. Intestinal transit and circular muscle mechanical activity were assessed 12 h after LPS injection. Tumor necrosis factor-α （TNF-α）, interleukin-10 （IL-10）, monocyte chemoattractant protein-1 （MCP-1） and inducible nitric oxide synthase （iNOS） mRNA in rat ileum were studied by RT-PCR 2 h after LPS injection. Nuclear factor-κB （NF-κB） activity in the intestine was also investigated at this time using electrophoretic mobility shift assay. In addition, antioxidant activity was determined by measuring malondialdehyde （MDA） concentration and superoxide dismutase （SOD） activity in the intestine 2 h after LPS iniection.RESULTS： Magnolol significantly increased intestinal transit and circular muscle mechanical activity in LPS- treated animals. TNF-α, MCP-1 and iNOS mRNA expression in the small intestine were significantly reduced after magnolol treatment in LPS-induced septic animals, compared with untreated septic animals. Additionally,magnolol significantly increased IL-10 mRNA expression in septic rat ileum. Magnolol also significantly suppressed NF-κB activity in septic rat intestine. In addition, magnolol significantly decreased MDA concentration and increased SOD activity in rat ileum. CONCLUSION： Magnolol prevents sepsis-induced suppression of intestinal motility in rats. The potential mechanism of this benefit of magnolol appears to be modulation of self-amplified inflammatory events and block of oxidative stress in the intestine.     

Phasic jaw motor episodes in healthy subjects with or without clinical signs and symptoms of sleep bruxism: a pilot study

Background

To investigate the association between each clinical diagnosis criterion for sleep bruxism (SB) and the frequency of jaw motor events during sleep.

Methods

Video-polysomnography was performed on 17 healthy adult subjects (mean age, 26.7?±?2.8 years), with at least one of the following clinical signs and symptoms of SB: (1) a report of frequent tooth grinding, (2) tooth attrition with dentine exposure through at least three occlusal surfaces, (3) morning masticatory muscle symptoms, and (4) masseter muscle hypertrophy. Episodes of rhythmic masticatory muscle activity (RMMA) and isolated tonic activity were scored visually. These variables were compared with regards to the presence or absence of each clinical sign and symptom.

Results

In 17 subjects, 4.0?±?2.5/h (0.1–10.2) RMMA and 1.0?±?0.8/h (0–2.4) isolated tonic episodes were observed (total episodes: 5.0?±?2.4/h (1.2–11.6)). Subjects with self-reported grinding sounds (n?=?7) exhibited significantly higher numbers of RMMA episodes (5.7?±?2.3/h) than those without (n?=?10; 2.8?±?1.8/h) (p?=?0.011). Similarly, subjects with tooth attrition (n?=?6) showed significantly higher number of RMMA episodes (5.6?±?3.1/h) than those without (n?=?11; 3.2?±?1.6/h) (p?=?0.049). The occurrence of RMMA did not differ between the presence and absence of morning masticatory muscle symptoms or muscle hypertrophy.

Conclusions

Clinical signs and symptoms frequently used for diagnosing SB can represent different clinical and physiological aspects of jaw motor activity during sleep.     

A pyridoindole antioxidant SMe1EC2 regulates contractility,relaxation ability,cation channel activity,and protein-carbonyl modifications in the aorta of young and old rats with or without diabetes mellitus

We studied the effects of treatment with SMe1EC, a hexahydropyridoindole antioxidant, on vascular reactivity, endothelial function, and oxidonitrosative stress level of thoracic aorta in young and old rats with or without diabetes mellitus. The rats were grouped as young control (YC 3 months old), old control (OC 15 months old), young diabetic (YD), old diabetic (OD), young control treated (YCT), old control treated (OCT), young diabetic treated (YDT), and old diabetic treated (ODT). Diabetes was induced by streptozotocin injection and subsequently SMe1EC2 (10 mg/kg/day, p.o.) was administered to YCT, OCT, YDT, and ODT rats for 5 months. In young and old rats, diabetes resulted in hypertension, weight loss, hyperglycemia, and hypertriglyceridemia, which were partially prevented by SMe1EC2. SMe1EC2 also inhibited the diabetes-induced increase in aorta levels of AGEs (advanced glycosylation end-protein adducts), 4-HNE (4-hydroxy-nonenal-histidine), 3-NT (3-nitrotyrosine), and RAGEs (receptors for AGEs). The contractions of the aorta rings to phenylephrine (Phe) and KCL did not significantly change, but acetylcholine (ACh) and salbutamol relaxations were reduced in OC compared to YC rats. Diabetes induction increased Phe contractions in YC and OC rats, KCL contractions in YC rats, and did not cause further inhibition in already inhibited ACh and salbutamol relaxations in OC rats. We have achieved the lowest levels of ACh relaxation in YD rats compared to other groups. SMe1EC2 did not change the response of aorta to ACh, salbutamol and Phe in YC rats, and ameliorated ACh relaxations in OC and YD but not in OD rats. In YDT and ODT rats, increased Phe and KCL contractions, high blood pressure, and impaired salbutamol relaxations were amended by SMe1EC2. Phe contractions observed in YD and OD rats as well as KCl contractions observed in OC rats were the lowest levels when the rats were treated with SMe1EC2. When the bath solution was shifted to cyclopiazonic acid (CYP) or CYP plus Ca²⁺-free medium, the contraction induced by a single dose of Phe (3?×?10^?6 M) was more inhibited in YD and OD than in YC but not in OC rats. In SMe1EC2-treated rats, neither the presence of CFM nor CFM plus CYP exhibited a significant change in response of aorta to a single dose of Phe. These findings suggest that α1-adrenergic receptor signaling is activated in both age groups of diabetic rats, diabetes activates K⁺-depolarization and calcium mobilization via Ca_V especially in the aorta of young rats, and sensitizes the aorta of old rats to the regulating effect of SMe1EC2. ACh relaxations were inhibited in YC rats, increased in OC rats and unchanged in YD and OD rats when aortic rings pretreated with TEA, an inhibitor of calcium-activated K⁺ channels (K_Ca), or 4-aminopyridine (4-AP), an inhibitor of voltage-sensitive K⁺ channels (K_V). ACh relaxations were inhibited in YCT, OCT, and YDT rats in the presence of 4-AP or TEA. In ODT rats, 4-AP did not change ACh relaxation but TEA inhibited. These findings suggest that the contribution of K_v and K_Ca to ACh relaxation is likely upregulated by SMe1EC2 when the relaxations were inhibited by aging or diabetes. We conclude that SMe1EC2 might be a promising agent for aging and diabetes related vascular disorders.     

Heat shock response decreases endotoxin-induced acute lung injury in rats

OBJECTIVE: Transient whole-body hyperthermia was reported to reduce lung damage in a rat with intra-abdominal sepsis produced by caecal perforation. METHODOLOGY: In order to determine the effect of heat shock response on acute lung injury induced by endotoxin, which plays a central role in the pathogenesis of sepsis, we instilled either saline or lipopolysaccharide (LPS) intravenously with and without heat pretreatment in rats. The heated rats had their rectal temperature raised to more than 40 degrees C for 13 min 18 h before intravenous administration of saline or LPS. RESULTS: We found that the lung leak was significantly increased among the rats given LPS intravenously with (median, 0.17; range, 0.15-0.22; n = 10) and without heat pretreatment (0.23; 0.17-0.30; n = 10) compared with those of saline-treated rats (0.13; 0.10-0.14; n = 10) (P < 0.05 in each). However, rats given LPS after heat pretreatment had significantly decreased lung leak index compared with those of LPS-treated rats without heat pretreatment (P < 0.05). Rats administered LPS intravenously showed increased myeloperoxidase activity without heat pretreatment (19.01; 9.34-28.00 U/g; n = 10) compared with that of saline-treated rats (7.09; 4.49-10.56 U/g; n = 5) (P < 0.05) (Fig. 2). Myeloperoxidase activity of the rats treated with LPS with heat pretreatment (5.57; 2.87-8.96 U/g; n = 10) was significantly decreased to the level of normal control compared with that of LPS-treated rats without heat pretreatment (P < 0.05). The levels of heat shock proteins (HSP72) in lung tissue, which were examined by western blot analysis, were increased over baseline levels at 23 h after hyperthermic stress. CONCLUSIONS: These observations show that brief heat shock response is associated with the induction of HSP72 protein synthesis and attenuated neutrophil recruitment and acute lung leak is induced by endotoxin in rats.     

Effects of free radical scavenger on acute liver injury induced by d-galactosamine and lipopolysaccharide in rats.

Aim: Acute severe liver injury still has a high mortality rate. Acute liver injury induced by a coadministration of d-galactosamine (GalN) and lipopolysaccharide (LPS) is an experimental model of fulminant hepatitis in rats. Our aim is to investigate the effects of free radical scavenger on the injury induced by GalN/LPS in rats. Methods: Free radical scavenger edaravone (3-methyl-1-phenyl-2-pyrazolin-5-one) was twice injected into rats 5 min before and 60 min after the GalN/LPS injection. Liver injury was biochemically and histologically assessed. The survival rate was examined 72 h after the intoxication. Results: In the GalN/LPS-treated rats, a marked elevation in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels was observed. On the other hand, edaravone significantly inhibited the elevation in serum AST and ALT levels. The efficacy of edaravone was also confirmedby histological analysis. Edaravone lowered the levels of proinflammatory cytokines TNF-alpha mRNA and interleukin-6 mRNA expression, antioxidative enzyme heme oxygenase-1 protein and myeloperoxidase activity, a marker of neutrophil infiltration, in rat livers. In addition, edaravone reduced the mortality rate in GalN/LPS-treated rats as compared to the rats without edaravone treatment. Conclusions: Free radical scavenger edaravone effectively ameliorated the liver injury induced by the GalN/LPS administration in rats, not only by attenuating oxidative stress, but also by reducing the expression of proinflammatory cytokines.     

Modulatory Role of Glutathione Monoester in Augmenting Age-Associated Neuronal Antioxidant System

An ever-increasing number of reports show the involvement of free radicals in the functional and structural changes occurring in the brain as a part of the normal aging process. This study aimed to assess the potential efficacy of glutathione monoester (GME) when administered intraperitoneally (12 mg/kg body weight) for 20 days on memory and the antioxidant defense system and lipid peroxidation in discrete brain regions such as cortex, striatum, and hippocampus of young and aged rats. Age-associated decline in memory and activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase, glutathione, vitamin E, and vitamin C, and elevated levels of lipid peroxidation and oxidized glutathione, were observed in all the brain regions studied (p < .001). GME administration was effective in restoring the antioxidant status and in decreasing lipid peroxidation level in aged rat brain regions.     

Expression change of TNF–α in myocardium and hepatic tissue of rats with compound stress of hyperthermia and lipopolysaccharide

ObjectiveTo investigate the expression characteristics of TNF-α in myocardium and hepatic tissue of rats with compound stress of hyperthermia and lipopolysaccharide (LPS).MethodsMale SPF Wistar rats were randomly divided into room temperature+physiological saline group (Group C), hyperthermia+physiological saline group (Group H), room temperature+LPS group (Group L) and hyperthermia+LPS group (Group HL). The rats were put in simulated climate cabin. Group HL and Group H were exposed in the environment at a dry bulb temperature (TDB) of (35.0±0.5) °C, while Group L and Group C were exposed in the environment at a TDB of (26.0±0.5) °C. The rats in Group HL and Group L were given tail intravenous injection of LPS 10 mg/kg, while the rats in Group H and Group C were given tail intravenous injection of 9 g/L NaCl 10 mL/kg. After the stress, immunohistochemical SABC staining method was used to detect the expression characteristics of TNF-α in myocardium and hepatic tissue of rats, and those rats were given routine pathological examinations.ResultsThe expression of TNF-α in myocardium and hepatic tissue in Group HL was enhanced remarkably, and the tissue damages of Group HL were severest.ConclusionsThe eardiotoxieity and hepatotoxicity caused by compound stress of hyperthermia and LPS is closely related to the expression of TNF-α.     

Gender differences in sensitivity of acetylcholine and ergonovine to coronary spasm provocation test

We examined the sex difference concerning the coronary artery response between ACh and ER in this study. We already reported the difference of coronary response between acetylcholine (ACh) and ergonovine (ER). We performed both ACh and ER tests of 461 patients (male 294 patients, female 167 patients, mean age 64.4 ± 11.3 years) during 23 years. Positive coronary spasm was defined as >99 % transient luminal narrowing with usual chest pain and/or ischemic ECG changes. Firstly, ACh was administered in incremental doses of 20/50/(80) μg into the RCA and 20/50/100/(200) μg into the LCA over 20 s. Secondly, ER was administered in a total dose of 40 μg into the RCA and of 64 μg into the LCA over 2–4 min. Intracoronary injection of ACh and ER provoked spasm in 221 patients consisting of 160 male patients and 61 female patients. In female patients, the spasm provoked by ACh was almost perfect except in two patients (59 patients, 96.7 %), while ER provoked spasm in only 20 patients (32.8 %). In male patients, provoked spasm by ACh (129 patients, 80.6 %) was significantly higher than ER (97 patients, 60.6 %). As a spasm provocation test, ACh is more sensitive than ER in both sexes and especially in females. We may select two pharmacological agents by sex differences to provoke coronary artery spasm in the cardiac catheterization laboratory in the future.