Therapeutic and protective effects of heparin on acute lung injury

Objective To investigate the therapeutic and protective effects of heparin on acute lung injury(ALI). Methods Sixty Wistar rats were randomly divided into five groups, normal control (A); lipopolysaccharide(LPS) (B); LPS and large-dose heparin (C); LPS and medium-dose heparin (D); LPS and minimal-dose heparin (E). Group A were made by injecting NS into the rat abdoments. The rat models of ALI were made by injecting LPS into the rat abdomens. Four hours later, the rats in Groups C, D, and E were injected with heparin of 1500, 250, and 75u/kg, respectively. All the rats were killed 12 hours later. Seven rats were randomly taken from each group for determination of the water contents in their lung tissues, and sent for histology. Contents of tumor necrosis factor-α(TNF-α), interleakin-1β(IL-1β) and interleakin-8 (IL-8) in plasma and bronchoalveolar lavagefluid (BALF) in the remaining five rats in each group were measured by ELISA. The WBC and its percentage of polymorphonuclear leukocyte (PMN) in BALF and plasma were counted. Results Thelevels of plasma and BALF TNF-α, IL-1β and IL-8 in Groups B, C, D and E were higher than those in group A ( F=7.71-21.10, q=5.22-7.80, P0.01). The BALF levels were higher than those in the plasma (t=4.32-10.05, P0.05). The levels in Groups C, D and E were markedly lower than those in Group B (q=3.64-5.70, P0.05). BALF WBC counts and PMN percentages in Groups B, C, D, and E differed significantly from those in Group A (F=58.00, 32.34; q=6.67-20.83; P0.05), and those in Groups C, D, and E differed significantly from those in Group B (q=6.31-14.07, P0.01). Conclusion Heparin has therapeutic and protective effects on acute lung injury.