BACKGROUNDPolymorphonuclear neutrophil (PMN), one of the most important inflammatory cells, functions throughout the initiation, progression and resolution of inflammation. This study aimed at investigating the relationship between PMN apoptosis and the lung injury after chest impact trauma.

METHODSPMNs were purified from rabbits subjected to the chest impact trauma and their apoptosis, necrosis, survival and respiratory burst were detected by flow cytometry. Meanwhile, lactate dehydrogenase and (LDH) [Ca2+]i were measured.

RESULTSThe delayed apoptosis of PMNs in bronchoalveolar lavage fluid was observed from 2 hours to 12 hours after trauma, and viable cells increased. Respiratory burst of PMNs in bronchoalveolar lavage fluid was increased significantly from 2 hours with the peak at 8 hours. Meanwhile, lactate dehydrogenase in bronchoalveolar lavage fluid was higher than that in control (P < 0.05) from 4 hours to 24 hours, and intracellular free Ca2+ in PMN was increased temporarily.

CONCLUSIONSRetention of PMN in tissues and the abnormality in apoptotic pathway inevitably generate persistent activation of PMN and excessive release of toxic substances, resulting in tissue injury. The temporary increase of intracellular free Ca2+ may be responsible for the delayed apoptosis of PMN.

Animals ; Apoptosis ; physiology ; Lung Injury ; Neutrophils ; physiology ; Rabbits ; Respiratory Burst ; physiology ; Thoracic Injuries ; complications

OBJECTIVETo explore the effect of substance P (SP) on the functional proteins on plasma membrane of neutrophil (Np).

METHODThe response of Np to SP was examined by measuring the level of respiratory burst, the activities of ACP and ALP, the fluoroscopy intensity of CR3, CD45 and FM-LP.

RESULTSIt was found that SP could increase respiratory burst of Np, decrease the activity of acid phosphatase (ACP), but had no effect on alkaline phosphatase (ALP). SP could also promote the amount of CD45, complement receptor type 3 (CR3) and N-Formyl-Met-Leu-Phe (FMLP) receptors.

CONCLUSIONThe results showed that the effects of SP on functional proteins in human Np membrane were universality and diversity. It implied that SP could affect various inflammation responses in Np.

Acid Phosphatase ; metabolism ; Humans ; Membrane Proteins ; physiology ; Neutrophils ; metabolism ; Respiratory Burst ; Substance P ; pharmacology

BACKGROUNDThe immunomodulatory effects of glucocorticoids (GCs) have been described as bimodal. High concentration of GCs exerts immunosuppressive effects and low levels of GCs are immunopermissive. While the immunosuppressive mechanisms of GCs have been investigated intensely, the immunopermissive effects of GCs remain unclear. A lot of studies showed GCs could exert rapid non-genomic actions. We herein studied the rapid immunopromoting effects of GCs.

METHODSWe observed the rapid (within 30 minutes) effects of corticosterone on respiratory burst of mouse peritoneal macrophages and studied their mechanisms. The superoxide anions were measured by cytochrome C reduction assay. Protein kinase C phosphorylation was measured by Western blotting and membrane fluidity was evaluated by fluorescence polarization measurement.

RESULTSThe 10(-8) mol/L and 10(-7) mol/L corticosterone rapidly increased the superoxide anions production by macrophages, which were insensitive to GC-receptor antagonist, mifepristone, and protein-synthesis inhibitor, cycloheximide. Corticosterone coupled to bovine serum albumin was able to mimic the effects of corticosterone. The effects were independent of protein kinase C pathway and the change in membrane fluidity.

CONCLUSIONSThe results indicate that corticosterone rapidly promote the superoxide anions production by mouse peritoneal macrophages may through non-genomic mechanisms. This study may contribute to understanding the effects of GCs under stress condition and the physiological significance of nongenomic effects of GCs.

Animals ; Corticosterone ; pharmacology ; Macrophages, Peritoneal ; drug effects ; physiology ; Male ; Mice ; Mice, Inbred BALB C ; Respiratory Burst ; drug effects ; Superoxides ; metabolism

To study the difference of changes on apoptosis, necrosis and respiratory burst of the polymorphonuclear neutrophils (PMN) in endotoxemia rat model. LPS (O(55)B(5), 5 mg/kg) was injected into abdominal cavity of 20 random normal Wistar rat. 2, 4, 8 and 12 hours after injection, the changes of apoptosis, necrosis and respiratory burst of the rats between PMN from the peripheral blood and from the bronchoalveolar lavage fluid were observed using the flow cytometer. At the same time, 5 uninjected rats were taken as control. The results demonstrated that the quantity proportions of apoptosis of PMN between the peripheral blood PMN and the bronchoalveolar lavage fluid PMN in rat's endotoxemia were similar. However, comparison with the uninjected LPS rat, the necrosis of peripheral blood PMN obviously increased and the respiratory burst capacity was clearly inhibited. Contrarily, the necrosis of bronchoalveolar lavage fluid PMN obviously decreased and the respiratory burst obviously increased in the injecting LPS rat. It was concluded that the necrosis and apoptosis displayed differently between the pulmonary and peripheral blood PMNs in endotoxemia. Under state of inflammation, the surviving PMN in tissue increased and kept the activated state due to tissue injury.
Animals ; Apoptosis ; Bronchoalveolar Lavage Fluid ; cytology ; Endotoxemia ; blood ; Necrosis ; Neutrophils ; physiology ; Pulmonary Alveoli ; pathology ; Rats ; Rats, Wistar ; Respiratory Burst

Human polymorphonuclear leukocytes (PMN) migrate into tissues in response to chemoattractants, yet it is not known whether this process alters the functional capabilities of the PMN. Using recombinant human interleukin-8 (rHIL-8, 100 ng/ml) as a stimulus, we compared a population of PMN that migrated through a polyvinylpyrrolidone-coated polycarbonate filter containing 8.0 microns diameter pores with PMN stimulated in suspension. PMN were analyzed by flow cytometry according to functional and phenotypic criteria. CD11b/CD16 expression was unaltered by chemotaxis. In contrast, chemotaxis enhanced phagocytosis of E. coli, independent of opsonization with IgG. Similarly, chemotaxis increased baseline hydrogen peroxide production. We conclude that the chemotactic motion of PMN "primes" the cell for increased oxidative burst activity and augments the ability of PMN to ingest bacteria. This increased functional capability is distinct from rHIL-8 stimulation and appears to be independent of complement-and Fc-receptor expression.
Antigens, CD/analysis ; Chemotaxis, Leukocyte/*physiology ; Escherichia coli/immunology ; Humans ; Neutrophils/physiology ; Phagocytosis/physiology ; Phenotype ; Receptors, IgG/analysis ; Respiratory Burst/physiology

OBJECTIVETo investigate the method and mechanism for exercise-related immunosuppression via the inhibitor of NADPH oxidase diphenyleneiodonium(DPI) and glutamine supplementation and on the function of neutrophils after overtraining.

METHODSFifty male Wistar rats were randomly divided into five groups: a negative control group (C), an overtraining group (E), an overtraining + DPI intervention group (D), an overtraining+ glutamine supplementation group(G) and combined glutamine + DPI intervention group(DG). After 36 - 40 h from the last training, eight rats were randomly selected from each group, and blood was sampled from the orbital vein. ELISAs were used to measure serum cytokine levels and lipid peroxidation in blood plasma. Flow cytometry was used to measure neutrophil respiratory burst and phagocytosis. The activity of NADPH oxidase was assessed by chemiluminescence and the gene expression of gp91(phox) and p47(phox) of the NADPH-oxidase subunit was checked by Western blot.

RESULTSCompared with group C, the plasma concentrations of NO increased in group G, and the NO, cytokine-induced neutrophil chemoattractant (CINC) concentrations in group DG increased significantly. The respiratory burst and phagocytosis function of neutrophils were decreased in group E, but in group DG were increased when compared with those of group E. After overtraining the expression of gp91(phox) and p47(phox) was up regulated in group E. There were no significant changes in other groups except group DG, in which the expression of gp91(phox) was down regulated. Compared with group E, the expression of gp91(phox) and p47(phox) was up regulated in group D, group G and group DG.

CONCLUSIONThe activation of NADPH oxidase is responsible for the production of superoxide anions, which may be related to the decrease in neutrophil function after over training and is the mechanism of exercise-related immunosuppression. The DPI treatment combined glutamine supplementation can reverse the decrease neutrophils function after overtraining in vitro.

Animals ; Dietary Supplements ; Glutamine ; pharmacology ; Hyperkinesis ; physiopathology ; Male ; Membrane Glycoproteins ; metabolism ; NADPH Oxidase 2 ; NADPH Oxidases ; antagonists & inhibitors ; metabolism ; Neutrophils ; metabolism ; physiology ; Onium Compounds ; pharmacology ; Oxidation-Reduction ; Rats ; Rats, Wistar ; Respiratory Burst ; physiology

The aim of this study was to examine the priming effect of sphingosine 1-phosphate (S1P) on fMLP-activated neutrophils, mainly to detect the neutrophil respiratory burst products, and to investigate the signaling pathway involved in S1P activity. Flow cytometry was used to evaluate the new isolated neutrophil; the superoxide anion output was detected indirectly by cytochrome C reduction in respiratory burst; the dihydro-rhodamine 123 was used to detect the intensity of respiratory burst; the signal transduction pathways of neutrophil respiratory burst were explored by Western blot. The results showed that after pretreated with S1P, the level of superoxide anion released by fMLP-activated neutrophils significantly increased; the Rhodamine 123 mean fluorescence intensity in S1P primed fMLP-activated neutrophils group was significantly higher than that in fMLP treatment group; PI3K and Akt proteins involved in the signal pathway of neutrophil respiratory burst. It is concluded that S1P is a new priming reagent, which primes respiratory burst of fMLP-activated neutrophils; this signal pathway may be that S1P interacts with its receptor, activates PI3K, then activates Akt-transmitting signals through NADPH oxidase, finally results in the respiratory burst.
Cells, Cultured ; Humans ; Lysophospholipids ; metabolism ; NADPH Oxidases ; metabolism ; Neutrophils ; metabolism ; physiology ; Proto-Oncogene Proteins c-akt ; metabolism ; Receptors, Lysosphingolipid ; metabolism ; Respiratory Burst ; Signal Transduction ; Sphingosine ; analogs & derivatives ; metabolism ; Superoxides ; metabolism

OBJECTIVETo study the chemical constituents in roots of P. fallax and their anti-oxidation activities in vitro.

METHODColumn chromatographic techniques were employed for isolation and purification of chemical constituents of the plant. The structures were elucidated on the basis of the spectral evidence and the physical and chemical character. The isolated compounds were screened with four anti-oxidation models in vitro.

RESULTSeven xanthones, 1,7-dihydroxy-2,3-methylenedioxyxanthone (1), 1-methoxy-2,3-methylenedioxyxanthone (2), 3-hydroxy-1,2-dimethoxyxanthone (3), 1,6,7-trihydroxy-2,3-dimethoxyxanthone (4), 7-hydroxy-1-methoxy-2,3-methylenedioxyxanthone (5), 1,3-dihydroxy-2-methoxyxanthone (6) and 1,3,7-trihydroxy-2-methoxyxanthone (7), were isolated from the roots of P. fallax. And compounds 1 - 7 showed different anti-oxidation activities in the different pharmacological models.

CONCLUSIONCompounds 2, 3, 5 and 7 were isolated from this plant for the first time. Xanthones from this plant showed anti-oxidation activities. The pharmacological activities of the pure compounds from this plant were also reported for the first time.

Animals ; Antioxidants ; isolation & purification ; pharmacology ; Lipid Peroxidation ; drug effects ; Macrophages ; physiology ; Mitochondria, Liver ; metabolism ; Oxidation-Reduction ; drug effects ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Polygala ; chemistry ; Rats ; Respiratory Burst ; drug effects ; Xanthones ; isolation & purification ; pharmacology