The changes of α-melanocyte-stimulating hormone in the serum of patients with TBI

Abstract

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 (±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. Key words: Traumatic brain injury; Alpha-melanocyte stimulating hormone; Tumor necrosis factor-α; Inflammation; Neuropeptide