Effect of early hyperbaric oxygen therapy on the expression of inducible nitric oxide synthase in acute spinal cord injury and it＇s therapeutic implications

Abstract

Objective To explore inducible nitric oxide synthase (iNOS) activity expression in the early stages of hyperbaric oxygen (HBO) therapy for acute spinal cord injury (SCI) and its therapeutic potential.Methods Seventy rats were randomly divided into a treatment group (including four sub-groups) and a control group (including three sub-groups).Acute SCI was induced at Ts-T9 in both groups using the modified Allen method.The four subgroups of the treatment group were treated with HBO at 2,4,6 and 8 hours after the injury,respectively.After 7 HBO therapy sessions,combined behavioral scores (CBSs) and evoked potentials were used to assessthe rats＇ limb function.Diazo colorimetric determination was used to detect iNOS expression and the nitrate reductase method was used to determine the content of nitric oxide.Results Compared with the control group and the other treatment subgroups,the 8 hour group recovered motor function the best.iNOS expression and NO production were reduced,and the differences were statistically significant.Conclusion HBO administered 8 hours after acute spinal cord injury had the best effect in reducing synthesis of iNOS and promoting motor function recovery. Key words: Hyperbaric oxygen; Spinal cord injury; Inducible nitric oxide synthase; Nitric oxide