The comparison of heparan sulfate and its fragments on the protection against extracellular histones during the pathogenesis of acute respiratory distress syndrome

Abstract

Objective: In order to explore the role of heparan sulfate (HS) during the pathogenesis of acute respiratory distress syndrome (ARDS) , the protective effect of HS and its fragments against extracellular histones was compared. Methods: Calf thymus histones (CTH) were injected via femoral vein to induce ARDS in rats. HS, HS fragments or saline was intraperitoneally injected (10mg/kg, Q6h, 24h) to test the protective effect against CTH. The ratio of wet/dry lung weight, protein content in bronchoalveolar lavage fluid (BALF) , total leukocyte and neutrophil count in BALF were measured. Results: After CTH injection, the ratio of wet/dry lung weight (5.7±0.95) was much higher than the saline control group (3.1±0.15). The protein content (0.47±0.086mg/ml) , total leukocyte[ (97.4±15.6l) ×10(4)/ml] and neutrophil (18±3.4/LPF) in BALF were obviously increased compared with the saline control group. The intervention of HS evidently decreased ratio of wet/dry lung weight (4.2±0.41) , protein content[ (0.26±0.019) mg/ml], leukocyte[ (61.3±5.74) ×10(4)/ml] and neutrophil (12±1.8/LPF) in BALF. HS fragments also decreased ratio of wet/dry lung weight, protein content, leukocyte and neutrophil count in BALF though the strength was much less than HS. Conclusion: HS and its fragments could provide protection against extracellular histones during the pathogenesis of ARDS. For the protective effect full length HS was much better than HS fragments.