OBJECTIVETo investigate whether pretreatment with alpha(1)-antitrypsin (AAT) can attenuate acute lung injury (ALI) in rabbits induced with endotoxin.

METHODSThirty-two healthy adult New Zealand rabbits were anaesthetized, tracheotomized and mechanically ventilated. They were then randomly divided into four groups (n = 8): (1) Infusion of Escherichia coli endotoxin [Lipopolysaccharide (LPS) 500 microg/kg] without AAT (Group LPS). (2) Infusion of AAT 120 mg/kg at 15 minutes after LPS (Group LAV). (3) Infusion of AAT 120 mg/kg without endotoxin (Group AAT). (4) Infusion of saline 4 ml/kg as control (Group NS). Arterial blood gases, peripheral leukocyte counts and airway pressure were recorded every hour for eight hours. Physiologic intrapulmonary shunting (Qs/Qt) was measured every four hours. After eight hours, blood samples were collected for measurement of plasma concentration and activity of AAT. Then, the animals were sacrificed, and bronchoalveolar lavage fluid (BALF) was collected for measurement of concentrations of total protein (TP), interleukin-8 (IL-8), tumor necrosis factor (TNF alpha, the activities of NE and AAT, total phospholipids (TPL) and disaturated phosphatidylcholine (DSPC). In addition, the wet-to-dry lung weight ratio (W/D) was measured.

RESULTSThe infusion of endotoxin induced decreases in arterial oxygen pressure (PaO(2)), peripheral leukocyte counts, total respiratory compliance (TLC) and the increases in peak pressure (P(peak)), Qs/Qt compared with the baseline values (P < 0.05). The increased plasma concentration but reduced activity of AAT was also found in contrast to that in Group NS (P < 0.05). In the BALF, the activity of AAT, TPL, DSPC/TPL were lower than those in Group NS (P < 0.05), but the concentrations of albumin, IL-8, TNF alpha, the activity of NE and the ratio of W/D were higher than those in Group NS (P < 0.05). The pretreatment of AAT attenuated the deterioration of oxygenation, the reduction of compliance and the deterioration of other physiological and biochemical parameters mentioned above.

CONCLUSIONPretreatment with AAT could attenuate endotoxin-induced lung injury in rabbits. Those beneficial effects of AAT might be due, in part, to reduction in the levels of mediators that could activate neutrophils, in addition to the direct inhibitory effect on neutrophil elastase.

Animals ; Endotoxins ; toxicity ; Lung Diseases ; prevention & control ; Rabbits ; Random Allocation ; alpha 1-Antitrypsin ; pharmacology ; therapeutic use

Animals ; Cytokines ; blood ; Endotoxins ; toxicity ; Fatty Liver ; chemically induced ; Liver Failure, Acute ; chemically induced ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVETo elucidate the effect of the low dosage endotoxin damage on the expression of the organic cation transporter 1 (OCT1) mRNA in hepatocytes and make an approach to the probable effect of dexamethasone on the expression of the OCT1 mRNA after endotoxin damage.

METHODS(1) The endotoxin damage model was established in rats; (2) The change of the expression of OCT1 mRNA in hepatocytes after endotoxin damage was observed by in situ hybridization method; (3) The change of the ultra structure of hepatocytes after endotoxin damage was observed with the electron microscope; (4) Dexamethasone was injected intraperitoneally before endotoxin damage in order to determine the influence of dexamethasone on the expression of OCT1 mRNA after endotoxin treatment.

RESULTSThe expression of OCT1 mRNA decreased until 16 hours (0.5745+/-0.012, P<0.01) after endotoxin treatment and then increased after this time point, which was still lower than the normal control; The expression of OCT1 mRNA in rat hepatocytes increased at each time point after endotoxin damage with dexamethasone treatment. It was highest at 16 hours (0.6327+/-0.007, P<0.01) after endotoxin damage, but it was still lower than that of the normal control.

CONCLUSIONEndotoxin could repress the expression of OCT1 mRNA even before the low dosage endotoxin inducing serious damage to the structure of hepatocytes; Dexamethasone could not induce the expression of OCT1 mRNA in normal hepatocytes, but could lighten the repression of endotoxin on the expression of OCT1 mRNA. And then the expression of OCT1 mRNA could increase at some extent after endotoxin damage with dexamethasone treatment.

Animals ; Dexamethasone ; pharmacology ; Endotoxins ; toxicity ; Male ; Organic Cation Transporter 1 ; genetics ; RNA, Messenger ; analysis ; Rats ; Rats, Wistar

Animals ; Brain Injuries ; blood ; cerebrospinal fluid ; chemically induced ; Endotoxins ; toxicity ; Female ; Male ; Natriuretic Peptide, C-Type ; analysis ; Neurotensin ; analysis ; Rabbits

OBJECTIVETo observe the binding power of polymyxin B (PMB) and its simulation peptide to lipopolysaccharide (LPS) and lipoid A.

METHODSLPS and lipoid A were separately coated on biosensor. 5 microl of PMB (0.01 microg/L) 5 microl of its simulating peptide 1 (PMBSP1 0.01 microg/L) and 5 microl of its simulating peptide 2 (PMBSP2, 0.01 microg/L) were respectively added into the hydrophobic sample pool. The combining power of PMB and its simulating peptides PMBSP1 and PMBSP2 to LPS and lipoid A was compared. RESULTS (1) PMBSP1 almost did not bind LPS and lipoid A, while PMB and PMBSP2 possessed high affinity with LPS and lipoid A. (2) The peak value (98.41 +/- 7.31) rad/s of PMBSP2 binding LPS was much higher than that (83.58 +/- 5.42) rad/s of PMB in binding LPS (P < 0.05). While the peak value of PMB in binding lipoid A was similar to that of PMBSP2. (3) The peak value of PMB binding LPS was significantly lower than that of PMB in binding lipoid A (P < 0.05). But there was no difference between the peak value of PMBSP2 in binding LPS and that of PMBSP2 in binding lipoid A. (4) PMBSP2 could bind to LPS and lipoid A in a shorter time to reach peak levels.

CONCLUSIONCompared with PMB, the PMBSP2 could bind to LPS and lipoid A in a shorter time. In addition, PMBSP2 exhibited similar affinity to LPS and lipoid A. This indicated that PMBSP might possess better anti-LPS activity due to its lack of space steric hindrance when PMBSP binding the lipoid A of LPS.

Cell Wall ; chemistry ; Endotoxins ; Gram-Negative Bacteria ; Lipopolysaccharides ; chemistry ; toxicity ; Peptides ; chemistry ; pharmacology ; Polymyxin B ; chemistry ; pharmacology

Animals ; Apoptosis ; Endotoxins/toxicity* ; Heart/drug effects* ; MAP Kinase Signaling System ; Myocardium/pathology* ; Rats ; Rats, Wistar ; Receptors, Calcium-Sensing/metabolism*

BACKGROUND: Endotoxin tolerance (ET) is a protective phenomenon in which pre-treatment with a tolerance dose of lipopolysaccharide (LPS) leads to dramatically elevated survival. Accumulating evidence has shown that peripheral T cells contribute to the induction of ET. However, what happens to T cell development in the thymus under ET conditions remains unclear. The purpose of this study was to analyze the alterations in thymocyte populations (double-positive [DP] and single-positive [SP] cells) under ET conditions. METHODS: Mice were intraperitoneally injected with LPS at a concentration of 5 mg/kg to establish an LPS tolerance model and were divided into two groups: a group examined 72 h after LPS injection (72-h group) and a group examined 8 days after LPS injection (8-day group). Injection of phosphate-buffered saline was used as a control (control group). Changes in thymus weight, cell counts, and morphology were detected in the three groups. Moreover, surface molecules such as CD4, CD8, CD44, CD69, and CD62L were analyzed using flow cytometry. Furthermore, proliferation, apoptosis, cytokine production, and extracellular signal-regulated kinase (ERK) pathway signaling were analyzed in thymocyte populations. The polymorphism and length of the T-cell receptor (TCR) β chain complementarity-determining region 3 (CDR3) were analyzed using capillary electrophoresis DNA laser scanning analysis (ABI 3730). RESULTS: Thymus weight and cell counts were decreased in the early stage but recovered by the late stage in a murine model of LPS-induced ET. Moreover, the proportions of DP cells (control: 72.130 ± 4.074, 72-h: 10.600 ± 3.517, 8-day: 84.770 ± 2.228), CD4+ SP cells (control: 15.770 ± 4.419, 72-h: 44.670 ± 3.089, 8-day: 6.367 ± 0.513), and CD8+ SP cells (control: 7.000 ± 1.916, 72-h: 34.030 ± 3.850, 8-day: 5.133 ± 0.647) were obviously different at different stages of ET. The polymorphism and length of TCR β chain CDR3 also changed obviously, indicating the occurrence of TCR rearrangement and thymocyte diversification. Further analysis showed that the expression of surface molecules, including CD44, CD69, and CD62L, on thymocyte populations (DP and SP cells) were changed to different degrees. Finally, the proliferation, apoptosis, cytokine production, and ERK pathway signaling of thymocyte populations were changed significantly. CONCLUSION These data reveal that alterations in thymocyte populations might contribute to the establishment of ET.
Animals ; CD4-Positive T-Lymphocytes ; Cell Differentiation ; Endotoxins/toxicity* ; Flow Cytometry ; Mice ; Signal Transduction ; Thymocytes ; Thymus Gland

This study was aimed to assess the effect of Shenfu injection on different circulation state. Using a microcirculation microscope system, we observed mice's auricle micro-artery diameter, density of capillary, blood velocity in different circulation state (i.e. normal state, epinephrine or endotoxin induced microcirculation disturbance state) after administering Shenfu injection into their caudal vein, and we compared the Shenfu group with Shenmai group and Dexamethasone group. The results showed that Shenfu injection causes the auricle microartery diameter to enlarge and the density of capillary and blood velocity to increase in different microcirculation state, and such effect is especially notable on the epinephrine induced microcirculation disturbance group and endotoxin induced microcirculation disturbance group; the effect of Shenfu injection is stronger than that of Shenmai injection and similar to Dexamethasone injection. In addition, Shenfu injection was shown to have remarkable effect on resisting the lowering of limb temperature when the mice are attacked by endotoxin.
Animals ; Blood Flow Velocity ; drug effects ; Drugs, Chinese Herbal ; administration & dosage ; pharmacology ; Ear ; blood supply ; Endotoxins ; toxicity ; Epinephrine ; toxicity ; Female ; Injections ; Male ; Mice ; Microcirculation ; drug effects ; physiology

OBJECTIVESTo identify significantly differentially expression genes of steroid-induced femoral head necrosis (SINFH) of rats by gene chip, and to find out the potential factors and molecular mechanisms that oxidative stress originate or strengthen the SINFH.

METHODSTwenty Wistar rats were divided into experimental group and control group randomly. E. coli endotoxin was given to all rats at a dose of 20 µg/kg body weight by daily i.p. for two times. Then methylprednisolone (40 mg/kg) or saline was daily injected into the left gluteus muscle of the rats in experimental group and control group respectively. Six weeks later, the mRNA was extracted from the femoral head of rats in every group, and the cDNA were obtained by inverse transcript, then carried out microarray detection. The quantitative RT-PCR was used to confirm the result of microarray, and the differentially expressed genes were analyzed for the functional annotation by gene ontology (GO).

RESULTSCompared to the control group, 190 genes in the experimental group were differentially expressed, with 52 up-regulated and 138 down-regulated. Of these genes, 102 are known (have deposited in GeneBank), while 88 of them are unknown. The known genes can be divided into several families according to their biological functions, such as: oxidative stress, apoptosis, signal transduction, angiogenesis, extracellular matrix, lipid metabolism, and gene transcription related genes. The results of quantitative RT-PCR are consistent with gene-chip results.

CONCLUSIONSThe occurrence of SINFH is a complicated process affected by multiple factors and signaling pathways. Our findings indicate that many genes which are involved in different signaling pathways were differentially expressed between SINFH rats and normal rats.

Animals ; Endotoxins ; toxicity ; Female ; Femur Head Necrosis ; chemically induced ; genetics ; Gene Expression ; Genomics ; Male ; Oligonucleotide Array Sequence Analysis ; Prednisolone ; adverse effects ; Rats ; Rats, Wistar

OBJECTIVETo observe whether electroacupuncture (EA) at Zusanli (ST 36) reduces endotoxin-induced hepatic injury in rats and to explore the mechanism.

METHODSForty male SD rats were randomly divided into 4 groups, a endotoxin group, an EA group, a normal group and a non-acupoint group. Hepatic injury rat model was prepared by injection of endotoxin (5 mg/kg) into the caudal vein, the normal group received the injection of the equal amount of saline; for the EA group, EA (2-100 Hz, 2 mA, 1.5 h) was given at "Zusanli" (ST 36) half an hour after modeling, and for the non-acupoint group, acupuncture was given at the point 5 mm lateral to and 5 mm below "Zusanli" (ST 36), and other treatments were as same as those in the EA group.

RESULTSInjection of endotoxin into the caudal vein could significantly increase TNF-alpha content in the liver and plasma ALT activity (P<0.01), which were decreased by EA (P<0.01) and were not significantly changed in the non-acupoint group (P>0.05).

CONCLUSIONThe abnormal increases of TNF-alpha content in the liver and plasma ALT activity induced by endotoxin can be decreased by EA at "Zusanli" (ST 36), protecting the organ, and the mechanism is possibly related with the decrease of TNF-alpha content in the liver.

Acupuncture Points ; Alanine Transaminase ; blood ; Animals ; Electroacupuncture ; Endotoxins ; toxicity ; Liver ; drug effects ; Male ; Rats ; Rats, Wistar ; Tumor Necrosis Factor-alpha ; analysis