OBJECTIVETo determine the effects of recombinant soluble complement receptor type I (sCR1) on the immune inflammatory reaction in acute spinal cord injury tissue of rats and its protective effects.

METHODSSD rat models of acute spinal cord injury were prepared by modified Allen's method. The motor function of the rat lower extremities in sCR1 group and normal saline (NS) group was evaluated by the tiltboard experiment at 12 h, 1 d, 3 d, 7 d, and 14 d. The neutrophil infiltration and C3c positive expression were observed. The myeloperoxidase activity was assessed in the injury tissue at 12 h, 1 d, 3 d, 7 d, and 14 d after injury in the two groups.

RESULTSThe motor function of rat in sCR1 group at 3 d, 7 d, and 14 d was obviously better than that in NS group (P<0.01, P<0.01, P<0.01). C3c positive expression in sCR1 group at each time point after injury was obviously less than that in NS group (P<0.01). The myeloperoxidase activity in sCR1 group at each time point after injury was obviously less than that in NS group (P<0.01).

CONCLUSIONSRecombinant soluble complement receptor type I (sCR1) can lessen the immune inflammatory reaction in acute spinal cord injury tissue and relieve secondary spinal cord injury by inhibiting the activation of the complement system.