| Objective:To investigate the effects of exercise preconditioning with different time nodes and different intensity on the levels of spinal cord inflammatory factors in rats with simulated dec Objective:To investigate the effects of exercise preconditioning with different time nodes and intensity on the levels of spinal cord inflammatory factors in rats with simulated decompression,and to explore the possible mechanism of exercise preconditioning to protect the spinal cord by regulating the levels of related inflammatory factors in the spinal cord of rats with simulated decompression by inhibiting key factors of NF κB signaling pathway.Methods:1.A total of 48 healthy male SD rats,aged 6 weeks and weighing 200±10g,were used.After one week of adaptive feeding,48 SPF rats were randomly assigned to 8 groups according to the principle of randomization:Normal control group(group C,n=6),simulated decompression group(DCS group,n=6),moderate exercise intensity group 1(group M1,n=6),moderate exercise intensity group 2(group M2,n=6),moderate exercise intensity group 3(group M3,n=6),high exercise intensity group 1(group H1,n=6),high exercise intensity group 2(H2 group,n=6),high exercise intensity group 3(H3 group,n=6).The rats in group C were fed normally without exercise training.The rats in DCS group were fed normally and did not do exercise training.The rats in M1 group received treadmill training at a speed of 20m/min for 1 hour,and the rats in H1 group received treadmill training at a speed of 30m/min for 1 hour.Two hours after the treadmill training,the rats in M1 group and H1 group were sent to hyperbaric oxygen chamber at the same time for decompression sickness modeling.The rats in M2 group received treadmill training at a speed of 20m/min for 1 hour,and those in H2 group received treadmill training at a speed of 3 0m/min for 1 hour.12h after the treadmill training,both groups were sent to hyperbaric oxygen chamber for simulated decompression modeling.The rats in M3 group received treadmill training at a speed of 20m/min for 1 hour,and the rats in H3 group received treadmill training at a speed of 30m/min for 1 hour.24h after the treadmill training,the M1 group and the H1 group were sent to the hyperbaric oxygen chamber at the same time for decompression sickness modeling.2.After modeling,the rats were observed for 40 60 minutes and scored.3.After the behavioral observation,the rats were dissected,and the spinal cord was detected by HE and Elisa.The levels of IL 1,IL 6 and TNF α were determined by Elisa.4.Blood was collected from the rat’s abdominal aorta to measure the number of white blood cells,red blood cells and platelets in the blood samples.5.According to the above results,the optimal exercise group was selected,and the expressions of IKKα,Ikkα and p65,the key proteins of NF kb signaling pathway,were detected respectively in group C,DCS and optimal exercise group by Western blot.Results:1.Behavioral scores in DCS group were significantly lower than those in C group(P<0.01),and those in H1 group and other exercise groups were significantly higher than those in DCS group.2.HE results showed that there were many small bubbles in the gray matter and white matter of the spinal cord of rats in the DCS group,the tissue structure was blurred,some nuclear fragmentation,nucleolysis,and obvious hemorrhagic spots.In H1 group,compared with DCS group,the bubbles in gray matter and white matter were significantly reduced,the hemorrhagic sites were reduced,and the cell integrity was improved.The other exercise groups had more air bubbles in both gray and white matter,and there was no significant improvement compared to the DCS group.3.Blood routine results:Compared with group C,the number of white blood cells in DCS group was significantly increased(P<0.01);Compared with the DCS group,the number of leukocytes in the H1 and H2 groups was significantly reduced,and the reduction was more significant in the H1 group than in the H2 group.Compared with C group,the number of red blood cells in DCS group was decreased,and the difference was significant(P<0.01).Compared with DCS group,the number of red blood cells in all exercise groups was increased,and there was a significant difference(P<0.05),and the significance was the largest in H1 group.Compared with C group,the number of platelets in DCS group was decreased,and the difference was significant(P<0.01).Compared with DCS group,the number of platelets in H1 group,M1 group,H2 group and H3 group increased,and there was a significant difference(P<0.05),and the significance was the largest in H1 group.3.Elisa results:Compared with group C,the contents of IL 1β,IL 6 and TNF α in spinal cord tissue of DCS group were significantly increased,with statistical significance(P<0.01).Compared with DCS group,the content of IL 1β in H1 group was significantly decreased(P<0.01),and that in other exercise groups was also decreased,with statistical significance(P<0.05).Compared with DCS group,the content of IL 6 in H1 group was significantly decreased,with statistical significance(P<0.05).Compared with DCS group,TNF α content in H1 group,M1 group and H3 group was significantly decreased(P<0.01),and was also decreased in H2 group,M2 group and M3 group,with statistical significance(P<0.05).5.WB results:Compared with C group,the expression levels of IKKα,Ikkα and p65 in the spinal cord of rats in DCS group were significantly increased(P<0.01);Compared with DCS group,the expression levels of IKKα,Ikkα and p65 in spinal cord of rats in H1 group were significantly decreased(P<0.01).Conclusion:Group H1 was the optimal exercise preconditioning group,and the optimal exercise preconditioning was treadmill running with an intensity of 30m/min for 1h 2h before decompression.Appropriate exercise preconditioning can reduce the inflammatory response of spinal cord in rats.The mechanism may be to regulate the level of inflammatory factors in spinal cord by inhibiting the expression of IKB-α,Ikk-α,p65 and other key proteins in NF κB signaling pathway,thus playing a role in protecting spinal cord tissue. |
