OBJECTIVETo 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.

METHODSSixty-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.

RESULTSCompared 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).

CONCLUSIONSUlinastatin has protective effect on phosgene-induced ALL Ulinastatin can inhibit the up-regulation of expression of MMP-9.

Acute Lung Injury ; drug therapy ; etiology ; metabolism ; Animals ; Glycoproteins ; therapeutic use ; Male ; Matrix Metalloproteinase 9 ; metabolism ; Phosgene ; toxicity ; Rats ; Rats, Sprague-Dawley

Objective:To study the efficacy of low-intensity focused ultrasound (LIFU) on neuropathic pain (NP) in mice, and its effect on the activation of astrocytes and the expression of pro-inflammatory cytokines were discussed.Methods:Thirty-six male C57BL/6J mice were randomly divided into three groups: sham operation (Sham) group and chroinc constriction injury (CCI) model group and treatment (CCI+ LIFU) group, 12 mice in each group.NP model was established by CCI on the sciatic nerve. The group of CCI+ LIFU received LIFU treatment for the anterior cingulate cortex (ACC) on the 7th day after surgery, the mechanical withdrawal threshold (MWT) on the affected side of mice was measured at preoperation 3, 6, 12, 18, 24, and 27 days after operation, respectively, H&E staining was used to observe pathological morphological changes in the ACC region, the expression levels of ACC region AQP4 and GFAP protein were detected by Western Blot and immunofluorescence, and the expression levels of ACC region pro-inflammatory cytokines IL-1β and TNF-α were detected by enzyme-linked immunosorption assay.Results:Compared with Sham group, MWT in the CCI group decreased from the 3rd day until the 27th day after surgery( P<0.05); Compared with the CCI group, the MWT in the CCI+ LIFU group increased on the 24th day after surgery, and was significantly higher than that of the CCI group on the 24th and 27th day after surgery ( P<0.05); LIFU stimulation did not produce significant pathological changes in the ACC region; Western Blot and immunofluorescence showed that AQP4 and GFAP protein expression in the ACC region were upregulated ( P<0.05) after peripheral nerve injury, while AQP4 and GFAP protein expression was downregulated after LIFU treatment ( P<0.05); Enzyme-linked immunosorbents showed that the expression of pro-inflammatory cytokines IL-1β and TNF-α in the region of ACC was upregulated ( P<0.05) after peripheral nerve injury, while the expression of IL-1β and TNF-α was downregulated after LIFU treatment ( P<0.05). Conclusions:LIFU can effectively relieve mechanical pain sensitivity symptoms in mice induced by CCI, possibly by inhibiting activation of astrocytes and neuro-inflammatory responses.