Abstract: ObjectiveTo study the characteristic of apoptosis and the expression of interleukin-1β(IL-1β)and caspase-3, as well as the relation among them after spinal cord injury(SCI) in rats.MethodsAdult SD rats were divided into two groups randomly: sham group and spinal cord injury group. The rats were killed at 1 h, 8 h, 24 h, and 72h after surgery. The expression of IL-1β and caspase-3 was determined with immunohistochemistry and the apoptosis was labeled by TUNEL.ResultsThere was only a few cells that expressed low level IL-1β and caspase-3 in sham group, but they both enhanced in SCI group within 8 h after operation, and then decreased to the level similar to sham group 72 h after operation. The rates of TUNEL-positive cells were similar with that of IL-1β and caspase-3 after SCI. There was positive correlation among expression of IL-1β and caspase-3 and apoptosis index.ConclusionExpression of IL-1β and caspase-3 increase and a large number of TUNEL-positive cells present after SCI in rats, and there is positive correlation among them.

Key words: spinal cord injuries, apoptosis, interleukin-1β(IL-1β), caspase-3