To explore the mechanisms of neurogenic inflammation and airway hyperresponsiveness of rat by inhaled sulfur / 中国应用生理学杂志

<p><b>AIM</b>To explore the physiopathological mechanisms of airway injury and the effect on the airway responsiveness of rat by inhaled sulfur dioxide(SO2).</p><p><b>METHODS</b>Sixteen SD male rats were divided randomly into 2 groups (n = 8): the control group and SO2 group. The control group was exposed o pure air. SO2 group was exposed to SO2 of the content 1.0 mg/(m(3) x h) 6h daily for consecutive 3 d. At 4th day, we determined the airway responsiveness, collected the bronchoalveolar lavage fluid (BALF), plasma and lung tissue. Then we counted the total cellular score in BALF, measured the plasma SP content and made the immunohistochemistry staining on the lung tissue (HE and SP methods).</p><p><b>RESULTS</b>Compared with the control group, the total cellular score in BALF and plasma SP content in SO2 group's increased significantly ( P < 0.01). HE staining showed there were a great deal of inflammatory cells infiltration under the tunica mucosa bronchiorum; and SP immunohistochemistry staining indicated there were significant changes in numbers of SP-IR positive fibers of SO2group.</p><p><b>CONCLUSION</b>Exposure to low concentration of SO2 would injure healthy rat's airway, and induce airway hyperresponsiveness, neurogenic inflammation is one of its critical pathophysiological mechanisms.</p>

Respiratory syncytial virus infection enhances airway hyperresponsiveness in guinea pigs and the underlined mechanism / 中国应用生理学杂志

<p><b>AIM</b>To study the relation between Respiratory Syncytial Virus infection and asthma development by measuring airway responsiveness (AR) and M2R function.</p><p><b>METHODS</b>Guinea pigs (n = 34) were randomly divided into 4 groups: Hep-2/NS group (group A, n = 9), RSV/NS group (group B, n =9), Hep-2/OVA group (group C, n = 8) and RSV/OVA group(group D, n = 8). On day 21 after infection we tested AR and M2R. Then counted eosinophils in BALF and observed pathological change.</p><p><b>RESULTS</b>Intraairway pressure(IP mmH20) of group B had no significant difference with group A(P > 0.01), and the extent of IP decrease also had no difference between groups A and B (P > 0. 05), but IP of C group were much higher than group A (P<0.05), with extent of IP decrease lower than group A (P < 0.05). And IP of group D were higher than group C (P < 0.01), with the extent of IP decrease much lower than group C (P < 0.05).</p><p><b>CONCLUSION</b>RSV infection could enhance OVA-induced M2R dysfunction, then develop AHR.</p>

[The role of stromal cell-derived factor and its receptor-CXCR4 in G-CSF-induced hematopoietic stem cell mobilization].

OBJECTIVE: To explore the role of stromal cell-derived factor (SDF-1) and its specific receptor CXCR4 in the G-CSF-induced hematopoietic stem/progenitor cells (HSPCs) mobilization in human healthy donor. METHODS: The changes of SDF-1/CXCR4 in bone marrow (BM) and peripheral blood (PB) of healthy donors during G-CSF-induced mobilization were detected by enzyme-linked immunosorbent assay (ELISA), immunohistological staining and flow cytometry. SDF-1 neutralizing antibody wes injected into BALB/c mice to further test its effect on mobilization. RESULTS: SDF-1 concentration in mobilized BM (mBM), steady state BM (ssBM) and PB were(7.23 +/- 0.66) microg/L, (5.43 +/- 0.35) microg/L and (5.42 +/- 0.52) microg/L, respectively. SDF-1 protein levels were decreased in the BM (P < 0.05) after 5-day G-CSF injection, and its concentration gradient between BM and PB disappeared (P > 0.05). Significant up-regulation of CXCR4 expression was observed on mBM CD34 cells in healthy donors. The rate of CXCR4 expression on CD34 cells in ssBM, mBM and mobilized PB were (40.98 +/- 21.56)%, (65.80 +/- 24.68)% and (27.54 +/- 26.03)%, respectively. Comparing with that in ssBM and mBM, CXCR4 expression on mobilized PB CD34+ cells were significantly decreased (P < 0.05). Inhibition of SDF-1 signal by blocking monoclonal antibodies significantly reduced G-CSF-induced mobilization in BALB/c mice. This resulted in significant decrease of white blood cell count and progenitors mobilized into peripheral circulation. CONCLUSION: G-CSF induces HSPCs mobilization by decreasing bone marrow SDF-1 and down-regulating CXCR4 expression on HSPCs.