Protective effect of exogenous cardiotrophin-1(CT-1)against spinal cord injury in rats

Objective To investigate the protective effect of exogenous cardiotrophin-1(CT-1)against spinal cord injury and the possible mechanism.Methods Ninety rats were evenly randomized into 9 groups,namely,before injury(0h)and 1,6,12 hours,1,2,3,6 and 12 days after injury.RT-PCR was used to examine the expression of CT-1,its receptor gp130,and leukemia inhibitory factor receptor(LIFR)in the injured spinal cord tissues.Rats were also divided into spinal cord injury model group,nerve growth factor(NGF)treatment group and CT-1 treatment group,receiving intradural infusion of normal saline,NGF,and rhCT-1(100μg·kg-1·d-1),respectively;the injured tissues were harvested at the 3rd day,one week and 2 weeks after injury for H-E and Nissl staining;and the neuron counts were compared between different groups.Sixty rats were divided into model group and CT-1 treatment group(n=30);the triceps muscle wet weight and total protein weight were compared between the two groups at 1 week,2 weeks and 4 weeks after spinal cord injury.Results CT-1mRNA expression had a transient significant increase after injury(P0.05),and then it decreased gradually;meanwhile,expression of its receptors increased consequently.The numbers of neurons and Nissl bodies were similar in CT-1-treated group and NGF-treated group,but the numbers of both groups were significantly more than that in the model control group(P0.05).In addition,the muscle wet weight and protein content in the CT-1-treated group were significantly higher than that in the model control group at 4 weeks and 12 weeks after injury(P0.05).Conclusion CT-1 exhibits a protective effect on the survival and function of neurons after spinal cord injury in rats.