Effect of melatonin on p38MAPKsignaling pathway in rats with phosgene-induced lung injury / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effect of melatonin (MT) on p38 mitogen-activated protein kinase (MAPK) signaling pathway in rats with phosgene-induced lung injury.</p><p><b>METHODS</b>Fifty specific pathogen-free male Sprague-Dawley rats were randomly divided into phosgene inhalation group, air control group, saline control group, MT treatment group, and SB203580 (specific inhibitor of p38 MAPK) group, with 10 mice in each group. All groups except the air control group were exposed to phosgene, and the animals were sacrificed 6 h later. Lung wet/dry weight (W/D) ratio and the content of malondialdehyde (MDA) and nitric oxide (NO) and activity of myeloperoxidase (MPO) in bronchoalveolar lavage fluid (BALF) were measured. The qualitative and quantitative expression of p38 MAPK and phospho-p38 MAPK (p-p38) was measured by immunohistochemistry (IHC) and Western blot, respectively. Inducible nitric oxide synthase (iNOS) level in lung tissue was determined by Western blot.</p><p><b>RESULTS</b>Compared with the air control group, the phosgene inhalation group had significantly increased lung W/D ratio and neutrophil count in BALF (P < 0.01); the MT treatment group had significantly lower neutrophil count and lung W/D ratio than the phosgene inhalation group (P < 0.05). IHC demonstrated that the air control group had relatively weak expression of p-p38 in lung tissue; the expression of p-p38 was significantly up-regulated after phosgene inhalation, and it was mainly distributed in infiltrating inflammatory cells and vascular endothelial cells, positive in the cytoplasm and nucleus of many cells. The distribution of p-p38-positive cells in the MT treatment and SB203580 groups was similar to that in the phosgene inhalation group, but the MT treatment and SB203580 groups had a significantly reduced number of cells with p-p38-positive nuclei and a significantly reduced intensity of p-p38 expression signals. The phosgene inhalation group had significantly increased content of MDA and NO and activity of MPO compared with the air control group (P < 0.01); the MT treatment and SB203580 groups had significantly reduced content of MDA and NO and activity of MPO compared with the phosgene inhalation group (P < 0.05), but had higher content of MDA and NO and activity of MPO than the air control group. The Western blot showed that the phosgene inhalation group had significantly increased expression of iNOS and p-p38 compared with the air control group (P < 0.01); the MT treatment and SB203580 groups had lower expression of iNOS and p-p38 than the phosgene inhalation group (P < 0.05).</p><p><b>CONCLUSION</b>MT and SB203580 have a significant protective effect in rats with phosgene-induced lung injury, and the mechanism may be associated with scavenging free radicals and inhibiting activation of p38 MAPK and expression of iNOS.</p>

Effects of adenovirus-delivered angiopoietin-1 siRNA on expression of matrix metalloproteinases in rats with acute lung injury induced by phosgene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of adenovirus-delivered angiopoietin-1 siRNA (Ad. Ang-1siRNA) on the expression of matrix metalloproteinase-2, 9 (MMP-2, 9) and tissue inhibitor of metallopro-teinase-1 (TIMP-1) in rats with acute lung injury (ALI) induced by phosgene (Psg).</p><p><b>METHODS</b>We first established a rat model of Psg-induced acute lung injury (ALI). The rats were randomly divided into 6 groups: air control group with exposure to air, air+adenovirus (air+Ad) group with caudal vein injection of 1×10(8) pfu/ml adenovirus 1 h after air exposure, air+Ad/Ang1 group with caudal vein injection of 1×10(8) pfu/ml Ad.Ang-1siRNA 1 h after air exposure, Psg group with exposure to 8.33 mg/L Psg (purity 100%, of the same volume as the inhaled air in the air control group) for 5 min, Psg+Ad group with caudal vein injection of 1×10(8) pfu/ml adenovirus 1 h after exposure to the same dose of Psg, and Psg+Ad/Ang1 group with caudal vein injection of 1×10(8) pfu/ml Ad.Ang-1siRNA 1 h after exposure to the same dose of Psg. Serum, bronchoalveolar lavage fluid (BALF), and lung tissue were collected 36 h after exposure. The protein expression of Ang-1, MMP-2, 9, and TIMP-1 in serum and BALF was determined by double-antibody sandwich ELISA. RT-PCR was used to determine the mRNA levels of Ang-1, MMP-2, 9, and TIMP-1 in lung tissue. The protein expression of MMP-2, 9 and TIMP-1 in lung tissue was determined by Western blot.</p><p><b>RESULTS</b>A rat model of Psg-induced ALI was successfully established. The levels of MMP-2, 9 in serum, BALF, and lung tissue were significantly increased in the Psg group and Psg+Ad/Ang1 group as compared with the control group (P<0.01); no significant change was observed in serum TIMP-1 protein expression (P>0.05); interestingly, TIMP-1 protein expression in BALF and lung tissue was significantly increased (P<0.01). Compared with the Psg group, the Psg+Ad/Ang1 group showed a significant decrease in MMP-2, 9 expression in BALF, serum, and lung tissue (P<0.05), but no significant change in protein expression of TIMP-1 was discovered (P>0.05).</p><p><b>CONCLUSION</b>Ad.Ang-1siRNA has a potential beneficial effect in rats with Psg-induced ALI through inhibition of MMP-2, 9 expression, but has no significant effect on the expression of TIMP-1.</p>

Dynamic changes of a group of cytokines in phosgene-induced lung injury and the function of ulinastatin / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the dynamic changes of a group of cytokines in phosgene-induced lung injury and the function of different dose of ulinastatin through animal experiment.</p><p><b>METHODS</b>104 male SD rats were randomly assigned into the control group, ulinastatin control group, phosgene treatment groups and different dose of ulinastatin intervention groups, 8 rats each group. Treatment groups were dynamic constant exposure in phosgene, and immediately injected ulinastatin intraperitoneal, and then the experimental animal, the lung tissue biopsy, lung wet/dry ratio, RT-PCR detection, the plasma for detection of Bio-Plex 18 cytokines.</p><p><b>RESULTS</b>Compared with the control group, plasma concentrations of IL-1α, IL-6, GM-CSF, TNF-α, INF-γ, MIP-3α, VEGF were increased significantly first (2 h), and gradually decreased with the passage of time , the difference was statistically significant (P < 0.05). Plasma concentrations of IL-4, IL-10 were decreased earlier (2h, 6 h) and increased later (24 h) (P < 0.05). The change of plasma concentration of IL-13 was not obvious earlier (2 h) and still rising later (24h), the difference was statistically significant (P < 0.05). After drug intervention, the levels of pro-inflammatory cytokines declined and the levels of anti-inflammatory cytokines raise by different degrees at different times in ulinastatin intervention groups, the difference was statistically significant. The degree of lung injury was improved than the phosgene treatment groups and better in high dose of ulinastatin intervention group. The expression of IL-10, IL-4, IL-13-mRNA of tissue increased in accordance with plasma results.</p><p><b>CONCLUSION</b>A group of cytokines are dynamicly changed in phosgene-induced lung injury by time. High dose of ulinastatin can improved phosgene-induced lung injury, regulate the synthesis and release of inflammatory cytokines and inhibit inflammatory react in a dose-dependent manner.</p>

Effects of phosphorylated mitogen-activated protein kinases on phosgene inhalation-induced lung injury in rats and its relationship with matrix metalloproteinase / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the effects of phosphorylated mitogen-activated protein kinases (MAPK), including the phosphorylated extracellular signal-regulated protein kinase 1/2 (p-ERK1/2), the phosphorylated protein p38 (p-p38), the phosphorylated c-Jun N-terminal kinase (p-JNK), on phosgene inhalation-induced lung injury and its relationship with matrix metalloproteinase 9 (MMP-9).</p><p><b>METHODS</b>According to the random number table, 30 male Wistar rats were divided into air control group (C), phosgene inhalation group (P), PD98059 (specific inhibitor of ERK1/2) group, SB203580 (specific inhibitor of p38) group, and SP600125 (specific inhibitor of JNK) group, with 6 rats in each group. The number of neutrophils in the bronchoalveolar lavage fluid (BALF) was counted and the lung wet-dry ratio (W/D) was examined. The serum levels of inflammatory factors TNF-α, IL-1β, IL-6, and IL-8 were determined with ELISA. The protein expressions of p-ERK1/2, p-p38, p-JNK, and MMP-9 in lung tissue were detected with Western blotting. The mRNA level of MMP-9 in lung tissue was detected with real-time fluorescence quantitative PCR. Data were processed with one-way analysis of variance (among groups) and SNK method (paired comparison).</p><p><b>RESULTS</b>Compared with those of group C [respectively (2.0 ± 0.7)×10(4) /mL and 3.7 ± 0.6], the number of neutrophils and W/D of group P [respectively (10.7 ± 1.4)×10(4) /mL and 7.6 ± 0.4] were increased. The number of neutrophils in group SB203580 and group SP600125 was respectively (8.3 ± 1.1)×10(4), (7.9 ± 1.3)×10(4)/mL, with W/D respectively 6.1 ± 1.4, 6.1 ± 0.9, all of which decreased as compared with those of group P (with P values all below 0.01). Compared with those of group C, the levels of TNF-a, IL-1β, IL-6, and IL-8 of group P were increased, but decreased in group SB203580 and group SP600125 compared with that of group P, though still higher than those of group C, and the differences were statistically significant (P < 0.05 or P<0.01). Protein quantities of p-p38 and p-JNK were higher in group P (respectively 1.19 ± 0.22 and 1.43 ± 0.14) than in group C (respectively 0.76 ± 0.06 and 0.74 ± 0.05). Compared with those of group P, the protein levels of p-ERK1/2 (0.47 ± 0.05) in group PD98059, p-p38 (0.88 ± 0.07) in group SB203580, and p-JNK (0.91 ± 0.07) in group SP600125 were significantly reduced (P < 0.05 or P < 0.01). The protein and mRNA levels of MMP-9 were higher in group P (respectively 2.23 ± 0.18 and 4.93 ± 0.12) than in group C (respectively 1.26 ± 0.14 and 1.80 ± 0.03). The protein and mRNA levels of MMP-9 in group SB203580 (respectively 1.58 ± 0.14 and 2.96 ± 0.09) and group SP600125 (respectively 1.55 ± 0.30 and 3.00 ± 0.13) were lower than those in group P (P < 0.05 or P < 0.01).</p><p><b>CONCLUSIONS</b>The phosgene inhalation can activate the MAPK signaling protein pathway by increasing expressions of p-p38 and p-JNK, which lead to an up-regulation of MMP-9, and this may contribute to the phosgene inhalation-induced lung injury.</p>

Protective effect of melatonin in rats with phosgene-induced lung injury / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the antioxidant effect of melatonin (MT) in the rats with phosgene-induced lung injury and its possible mechanism.</p><p><b>METHODS</b>Fifty male SD rats were equally randomized into phosgene exposure group, air control group, MT treatment group, dexamethasone (DX) treatment group, and negative control group. All groups except the air control group were exposed to 8.33 mg/L phosgene for 5 min, and the MT treatment group, DX treatment group, and negative control group were injected with MT (10 mg/kg), DX (2.5 mg/kg), and 1% ethanol saline (1 ml/kg), respectively, via the caudal vein 1 hour after exposure. The rats were sacrificed 6h later. Then, the wet/dry ratio of the lung, the total protein content and neutrophil count in bronchoalveolar lavage fluid (BALF), and the malonaldehyde (MDA) content and superoxide dismutase (SOD) and myeloperoxidase (MPO) activities in lung homogenate were measured; pathological observation was made on the lung tissue under an optical microscope; the protein expression of inducible nitric oxide synthase (iNOS) and NF-κB in the lung tissue was measured by Western blot.</p><p><b>RESULTS</b>Compared with the air control group, the phosgene exposure group showed significantly increased wet/dry ratio of the lung and total protein content and neutrophil count in BALF (P < 0.01) as well as significantly increased MDA content and MPO activity in the lung tissue (P < 0.05). Compared with the phosgene exposure group, the MT treatment group showed significantly decreased MDA content and MPO activity and significantly increased SOD activity (P < 0.01), and the MT treatment group and DX treatment group showed significantly decreased protein expression of iNOS and NF-κB (P < 0.01).</p><p><b>CONCLUSION</b>MT has protective effect in phosgene-induced lung injury, and its protective mechanism may be associated with scavenging free radicals and inhibiting expression of iNOS and NF-κB.</p>

Expression and role of mitogen activated protein kinases signaling pathway in lung injury induced by phosgene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>This study aimed to investigate the expression and role of the mitogen activated protein kinases (ERK1/2, P38, JNK) in phosgene induced lung injury in rats in vivo.</p><p><b>METHOD</b>30 male wistar rats were randomized into the group as follows, Gas inhalation control group, Phosgene inhalation group, and the following groups of the inhibitors of MAPK, involving SP600125, PD98059 and SB203580, 6 animals in each group, we copy the model of phosgene-induced lung injury, used the directional flow-inhalation device, the air control group inhaled the air, and the intervention groups were given PD98059 (intraperitoneal injection), SB203580 (hypodermic injection), SP600125 (intravenous) respectively before the inhalation of phosgene. The locations and quantities of three subfamilies of MAPKs (ERK1/2, P38, JNK) and p-MAPKs (p-ERK1/2, p-P38, p-JNK) were analyzed by immunohistochemistry and Western Blot analysis respectively; The histopathological changes of lung tissues, the number of neutrophil cells and the W/D were examined.</p><p><b>RESULT</b>There were rare p-ERK1/2, p-P38 and p-JNK positive expression in alveolar and airway epithelial cells in control group. while the positive cells increased strikingly in phosgene inhalation groups, these cells involved in this process mainly included alveolar epithelial cells, air way epithelial cells, pleural mesothelial cells, infiltrative inflammatory cells, interstitium fibrocytes. After the intervention of the specific inhibitor, the positive cells decreased. As Western Blot analysis show, Protein quantities of p-P38 and p-JNK were higher in phosgene inhalation groups than those in control group, and the differences were significant (P < 0.05). Protein quantities of p-ERK1/2, p-P38 and p-JNK were lower in intervention groups than phosgene inhalation group, and the differences were significant (P < 0.05, P < 0.01). The lung injury in phosgene inhalation groups was more severer compared with the control group, the typical pathological characters of acute lung injury were discovered, the increase of the number of neutrophil cells and W/D. After the intervention of the specific inhibitor SP600125 and SB203580, the number of neutrophil cells and W/D reduced, and the differences were significant (P < 0.05, P < 0.01).</p><p><b>CONCLUSION</b>Phosgene inhalation may activate the MAPK signaling pathway, and the expression of the phosphorylation of MAPKs increased, especially the P38 ang JNK. The results may contribute to the lung injury induced by phosgene.</p>

Effects of dexamethasone pretreatment on expression of matrix metalloproteinase-9 in rats with acute lung injury induced by phosgene / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the effects of dexamethasone on expression of matrix metalloproteinase-9 (MMP-9) in rats with acute lung injury induced by phosgene.</p><p><b>METHODS</b>The rats were randomly divided into 3 groups: normal control group that consists of the rats with air exposure, phosgene group that consists of the rats with phosgene exposure and dexamethasone group that consists of the rats with phosgene exposure after 2.5 mg/kg dexamethasone being injected. Wet and dry ratio of the lung (W/D) was calculated, and leukocyte count and total protein content of bronchoalveolar lavage fluid (BALF) were recorded at 2 h after exposure. The concentrations of MMP-9 in the serum and BALF were measured by enzyme-linked immunosorbent assay. The pathologic changes of lung tissues were observed under light microscopy. The immunohistochemistry and the RT-PCR were used to detect the contents of MMP-9 in the lung tissue.</p><p><b>RESULTS</b>Compared with phosgene group, the lung W/D, protein content and WBC count in of BALF dexamethasone group was significantly decreased (P < 0.01). MMP-9 levels of the serum and BALF in dexamethasone group were (4.799 +/- 0.043) microg/L and (15.052 +/- 0.029) microg/L, respectively, which were significantly lower than those [(9.439 +/- 0.100) and (20.640 +/- 0.446) microg/L] in phosgene group (P < 0.01). Compared with phosgene group (2.789 +/- 0.282),the expression level (1.183 +/- 0.260) of lung MMP-9 mRNA in dexamethasone group was significantly lower than that in phosgene group (P < 0.01). Histological experimental results showed the marked hyperemia and thickening of alveolar walls and stroma cells infiltrating and more visible alveolar structure damage of alveolar walls in phosgene group while the alveolar structure and the alveolar walls were clear and slightly thickened with inflammatory cells in dexamethasone group. Immunohistochemical results showed that MMP-9 protein expression levels of lung and bronchus tissues in normal control group and dexamethasone group were weakly positive, which in phosgene group were strongly positive.</p><p><b>CONCLUSION</b>Dexamethasone has a beneficial effects on acute lung injury induced by phosgene in rats due to the inhibiting MMP-9.</p>

The changes of the ratio of angiopoietin-2 to angiopoietin-1 in the acute lung injury induced by phosgene in rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the relationship between the indicators of lung injury and the ratio of angiopoietin-2 (ang-2) to angiopoietin-1 (ang-1) in serum of rats with acute lung injury induced by phosgene.</p><p><b>METHODS</b>Eighty four adult male SD rats were randomly divided into 13 phosgene groups and 1 control group. Control group was exposed to fresh air for 5 minutes; the phosgene groups were exposed to phosgene (100% purity of 8.33 mg/L phosgene ) for 5 minutes. At different time points after exposure, the wet/dry weight ratio of mouse lungs was examined, the levels of ang-1 and ang-2 in serum of rats were detected with ELISA assay, and the white blood cell count and total protein levels in bronchoalveolar lavage fluid (BALF) of rats were measured.</p><p><b>RESULTS</b>In 48 h after exposure,the serum ang-2, lung wet/dry weight ratio, BALF white blood cell count, protein concentration tended to increase with time, and the serum ang-1 tended to decrease with time. The ratios of ang-2 to ang-1 at 6, 8, 10, 12, 14, 16, 18, 20, 22, 24 and 48 h after exposure in phosgene groups were significantly higher than that in control group (P < 0.05 or P < 0.01). There were the positive correlations between ang-2 and lung wet/dry ratio, BALF white blood cell count or protein concentration (P < 0.01). There were the negative correlations between ang-1 and lung wet/dry ratio or BALF white blood cell count (P < 0.01). There were the positive correlations between the ratio of ang-2 to ang-1 and lung wet/dry ratio, BALF white blood cell count or protein concentration (P < 0.01).</p><p><b>CONCLUSION</b>After exposure of rats to phosgene, there is a positive correlation between the ratio of ang-2 to ang-1 and lung injury indicators, which may be an early indicator of the severity of phosgene-induced acute lung injury.</p>

Protective effects of ulinastatin on phosgene-induced acute lung injury and relation to matrix metalloproteinase-9 / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To observe the protective mechanism of ulinastatin on mice with acute lung injury induced by exposure to phosgene and its relationship to the expressions of matrix metalloproteinase-9 (MMP-9) in the lung tissues.</p><p><b>METHODS</b>Sixty-four healthy male SD rats were randomly divided into two groups: the experimental group and the control group. 32 rats in the experiment group were randomly subdivided into four groups: rats with phosgene exposure group, rats with phosgene exposure after saline injected group, rats with phosgene exposure after dexamethasone injected group. 32 rats in the control group were randomly subdivided into four groups: rats with air exposure group, pretreated with ulinastatin before air exposure group, pretreated with saline before air exposure group, pretreated with dexamethasone before air exposure group, 8 animals in each group. After pretreated with the same dose of ulinastatin, saline, dexamethasone respectively, 32 rats in the control groups were exposed to the air on the same condition respectively for 5 min. While after pretreated with the same dose of ulinastatin, saline, dexamethasone respectively, 32 rats in the experiment groups were exposed to the phosgene which the concentration was 8.33 mg/L and with 100% purity for 5 min. The lung wet/dry (W/D) weight ratio was calculated, and total protein content and BALF leukocyte count were detected. The immunohistochemistry was used to detect lung tissue protein expression MMP-9 while enzyme-linked immunosorbent method was employed to detect MMP-9 in serum levels and enzyme original gelatinases spectrum method to detect BALF MMP-9 enzyme original content.</p><p><b>RESULTS</b>Compared with A1, A2, A3, A4 group, the lung W/D, BALF of protein content and WBC count in B1 and B2 group rats were significantly increased, and the difference was statistically significant (P < 0.01). There was statistically significant difference in lung W/D, BALF of protein content and white blood cell count between B1,B2 group and the B3 and B4 rats (P < 0.01). Histological experimental results showed marked hyperemia of alveolar walls, thickening in the lungs, alveolar walls and stroma cells infiltrating and more visible alveolar structure damage in B1 and B2 rats while the alveolar structure, the alveolar walls were clear and slightly thickened with inflammatory cells in B3 and B4 rats. Immunohistochemical result showed that the individual rats, lung and bronchus organization MMP-9 protein were weakly positive, B1 and B2 group MMP-9 protein expression was strongly positive,B3 group and the group MMP B4 lung tissue protein expression-9 weakens, restored to the normal lung tissue of weakly positive expression level. ELISA and gelatinases spectrum testing showed B1 and B2 rats, serum MMP-9 enzyme activity and content increased compared with A1, A2, A3, A4 group, the differences were statistically significant (P < 0.01), and B1, B2 group compared with the B3 and serum B4 group MMP-9 enzyme activity and the differences were obviously decreased, with statistically significant difference (P < 0.01).</p><p><b>CONCLUSIONS</b>Ulinastatin has protective effect on phosgene-induced ALL Ulinastatin can inhibit the up-regulation of expression of MMP-9.</p>

Observation on the protective effect of hyperoxia solution on the acute lung injury caused by phosgene poisoning / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the protective effect of hyperoxia solution on acute lung injury caused by phosgene poisoning by observing the changes of PaO2 and malondialdehyde (MDA) contents, superoxide dismutase (SOD) activity in serum and Glutathione (GSH/GSSG) contents in lung tissues.</p><p><b>METHODS</b>The rabbits were divided into normal control group, hyperoxia solution (H0) and balance salt (BS) groups. Group HO and Group BS inhaled phosgene and the former was given intravenously hyperoxia solution (which was replaced by balance salt solution in Group BS). The content of MDA and the activity of SOD in serum were observed at different time points, the amount of GSH and GSSG in lung tissue were also measured.</p><p><b>RESULTS</b>(1) The serum MDA contents increased and PaO2, SOD activity decreased significantly in Group HO and Group BS along with time increasing as compared with control group. The contents of GSH in lung tissue decreased in two groups compared with that in control group, however the contents of GSSG ascended instead. (2) At 3 and 8 h of the experiment, PaO2 of Group HO [(9.91 +/- 0.49), (9.15 +/- 0.46) mm Hg respectively] were significantly higher than those of Group BS [(9.03 +/- 0.76), (8.11 +/- 0.57) mm Hg respectively] (P < 0.01). The contents of MDA of Group HO (3.66 +/- 0.35), (5.31 +/- 0.15) micromol/L respectively] were lower than those of Group BS [(4.32 +/- 0.26), (7.4 +/- 0.33) micromol/L respectively] (P < 0.01). SOD activity in Group HO [(237.37 +/- 29.96), (208.10 +/- 18.80) NU/ml respectively] were higher than those of Group BS [(195.02 +/- 21.44), (144.87 +/- 21.26) NU/ml respectively] (P < 0.05 or P < 0.01). The content of GSSG lung tissue in Group HO (423.67 +/- 38.21) micromol/L were lower than those of Group BS (523.85 +/- 43.14) mol/L (P < 0.01). There were no significant differences in the content of GSH in lung tissues between Group HO and group BS.</p><p><b>CONCLUSION</b>Hyperoxia solution can reduce acute lung injury of rabbits following phosgene poisoning.</p>

Effect of phosgene on apoptosis of alveolar type II cells and vascular endothelial growth factor in exposed mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the apoptosis of alveolar type II cells, alterations of vascular endothelial growth factor (VEGF), VEGF receptor (Flt1) in serum and lung and expression of VEGF mRNA in lung in pulmonary edema mice induced by phosgene.</p><p><b>METHODS</b>Twenty-six BALB/C mice were randomly divided into 2 groups: control group, exposed group (13 mice in each group). Mice of exposed group were intoxicated by inhalation of phosgene 11.9 mg/L for 5 minutes. Mice of control group were treated as the same way by inhalation of air. Isolation of mice alveolus type II cells 4 h after intoxication was carried out to observe their apoptosis under electron microscope. Contents of VEGF and Flt1 in lung and serum by ELISA, and expression of VEGF mRNA were determined.</p><p><b>RESULTS</b>Alveolar type II cells were identified by tannic acid staining and electron microscopy. After exposed to 11.9 mg/L of phosgene for 5 minutes, the apoptotic body in alveolus type II cells was found in exposed group. The contents of VEGF in serum and lung and Flt1 in lung of exposed mice [(134.07 +/- 120.26), (477.76 +/- 98.06), (1,2818.48 +/- 2,304.15) pg/ml] were significantly lower than those of control group [(445.57 +/- 173.30), (1,026.87 +/- 474.56), (21,976.51 +/- 7,421.01) pg/ml, P < 0.05] but the content of Flt1 in serum [(2,369.56 +/- 381.70) pg/ml] was higher than that in control group [(1,898.00 +/- 453.69) pg/ml, P < 0.05]. The expression of VEGF mRNA in pulmonary edema mice was decreased.</p><p><b>CONCLUSION</b>Phosgene can induce apoptosis of alveolar type II cells, and decrease in the content of VEGF and Flt1, and expression of VEGF mRNA in lung.</p>

Effect of acute phosgene inhalation on antioxidant enzymes, nitric oxide and nitric-oxide synthase in rats / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effect of acute phosgene inhalation on the antioxidant enzymes, nitric oxide (NO) and nitric oxide synthase (NOS) in rats.</p><p><b>METHODS</b>Phosgene was produced by decomposing bis (trichdomethyl) carbonate in the presence of N,N-dimethyl formamide. SD rats were randomly divided into two groups: control and phosgene exposure groups. In a special experimental device with equipment modulating the gas flow, phosgene exposed rats inhaled phosgene quantitatively for five minutes. Two hours later, all the rats were sacrificed and the ratio of wet weight to dried weight of lung (WW/DW) was calculated. Peripheral blood, serum and liver were collected to examine the activities of antioxidant enzymes including glutathione S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), NOS, and NO level. The total content of proteins were also determined.</p><p><b>RESULTS</b>The WW/DW ratio of lung in phosgene exposure group was much higher than that in control group (P < 0.01). The activities of GST in serum and liver of phosgene exposure group increased significantly (P < 0.05). The activities of SOD, CAT, GSHPx and NOS in serum or blood and liver of phosgene exposure group were also increased significantly (P < 0.05). But the content of NO was significantly decreased (P < 0.01).</p><p><b>CONCLUSION</b>Acute phosgene inhalation may cause a dramatically changes of several antioxidant enzyme activities, and acute injury of liver to some extent in rats. The latter is related to reactive oxygen species. But the elevation of antioxidant enzyme activities suggests that antioxidative treatment for acute phosgene poisoning should not be considered first.</p>

Assessment of Voice Disorder following Inhalation Injury / 대한산업의학회지

Objective: Injury to the airway, found in 25% to 35% of patients admitted to major burn center, is now the leading cause of death in burn patients. Significant inhalation injury can increase the patient mortality rates by up to 20%. Toxic compounds in smoke can include phosgene, ammonia, sulfur dioxide, and chlorine from plastics and various oxides and aldehydes from burning wood. These compound directly injure airway epithe hal cells, causing an intense inflammatory response with significant edema. After the critical problem is controlled with intensive care in inhalation burn patients, less critical but significant laryngeal function such as protection, phonation and deglutition may often be overlooked. METHOD & RESULT: We have experienced a male patient who was injured by inhalation of toxic compound in ship under cohstruction. He have suffered from pulmonary problem, bronchiohitis obhiterans. Voice disorder was assessed and managed by otolaryngologists after resolving the pulmonary lesion. CONCLUSION: Evaluation and treatment of patients suspected of inhalation injury should include anatomical and functional aspects of the larynx as well as critical problem of the airway.