RESUMO
Objective To study the effects of α-melanocyte-stimulating hormone (α-MSH) on excessive inflammatory response of patients to traumatic brain injury (TBI) so as to prevent against the development of the secondary injury by observing the changes of α-MSH level in the serum of patients with TBI,and the relationships of the levels of serum α-MSH with the severity of TBI,and with the levels of tumor necrosis factor-α (TNF-α).Methods A total of 48 patients with acute TBI were divided into three groups according to GCS score:severe group with GCS 3-8 (n =18),moderate group with GCS 9-12 (n =16),and mild group with GCS 13-15 (n =14).Ten healthy volunteers were recruited as a control group.The blood samples were collected within 24 h and 3 d,5 d,7 days after injury.The concentrations of α-MSH and TNF-α in the separated serum were measured by double antibody sandwich enzyme-linked immunosorbent assay (ELISA).All variables were presented as ((x)±s).Repeated measures and analysis of variance and further multiple comparisons were carried out to compare variables.When necessary,the Student's t test was utilized.Pearson correlation analyses were performed to determine the correlations between variables.Results The serum α-MSH levels in the three TBI groups were lower than that in the control group (P ＜ 0.05).And the severer injury was,the lower α-MSH level was.The lowest α-MSH levels dropped to the trough on the 3rd day or the 5th day after TBI [severe group:(9.65 ±4.21) pg/mL,moderate group:(10.69 ±4.30) pg/mL,mild group:(18.89 ±7.19) pg/mLvs.control:(45.67 ± 10.95) pg/mL].While the serum TNF-α levels in three TBI groups were higher than that in the control group (P ＜ 0.05),and the TNF-α level was higher in the severer group.The peak values of TNF-α in the three TBI groups reached on the 3rd day after TBI [severe group:(37.24 ± 18.28) pg/mL,moderate group:(26.19 ±6.78) pg/mL,mild group:(18.60 ±7.83) pg/mL vs.control:(10.74 ± 1.71) pg/ mL].There were negative correlations between the levels of serum α-MSH and TNF-α at four intervals.Conclusions In patients with TBI,the serum levels of α-MSH decreased,and the lowest levels of α-MSH dropped to the trough on the 3rd day or the 5th day after TBI.While the levels of TNF-α increased,and the peak values reached on the 3rd day after TBI.And as the injury was more severe,these changes were more significant.There were negative correlations between the serum α-MSH levels and TNF-α levels in general.