Effects of melatonin on expression of IL-10 in rats with acute spinal cord injury at different periods

Aim: To explore the effects of melatonin ( MT) on expression of interleukin-10( IL-10) in acute spinal cord injury ( SCI) in rats,and to investigate the function of MT in the inflammatory response and nerve repair after acute SCI. Methods: A total of 108 Sprague-Dawley ( SD) rats were randomly divided into 3 groups: model group,treatment group and control group. The first two groups acute SCI model were established by using the modified Allen's weight drop ( WD) method at T 12 level,and the control group was removed lamina only. At 10 min after the model establishment,5% ethanol was given to the model group and 100 mg / kg of MT to treatment group. At 1 d,2 d,3 d,5 d,7 d,the function of the spi-nal cord was assessed by Basso Beattie Bresnahan locomotor rating scale ( BBB scale) ,the blood samples and spinal cord were obtained to measure the levels of IL-10 and IL-10 mRNA. At 3 d,6 samples of spinal cord from aorta perfusion model were taken in each group for histological examination using HE and Immunohistochemical SP staining methods. Results: Rats of model group and treatment group showed severe lower limb neurological dysfunction after surgery. At 3 d,5 d and 7d,the difference between them in BBB scale had statistical difference ( P 0. 01) . IL-10 mRNA levels of treatment group was highest at each time point,and it was consistent with the IL-10 levels at serum and the IL-10 positive cells. The differ-ence between each two groups had statistical significant ( P 0. 01) ,immunohistochemistry showed that more of IL-10 dis-tributed at the cytoplasm of endothelial cell,nerve cells and glial cell. Conclusion: This study indicates that MT suppress lipid oxidation reactions and inflammatory response by increasing the secretion of IL-10 in central canal surrounding endo-thelial cell,nerve cells and glial cell.