Effect of inflammatory cytokines of blood serum on cell metabolism of bilateral hippocampus in the first episode depression: a magnetic resonance spectroscopy study

Abstract

Objective To explore the cell metabolism of the bilateral hippocampus effected by the inflammatory factor of blood serum in the development of the depression. Methods Using Proton magnetic resonance spectroscopy 1H-MRS technology to detect multiple metabolic indices of the bilateral hippocampus of 20 first episode depression patients and 20 healthy persons, and detecting the levels of IL-6, IL-2, IL-10 in blood serum were detected.Finally the correlation between them was analyzed. Results Compared with the healthy group, the values of Glx/ Cr and NAA/ Cr were reduced in left hippocampus(Glx/Cr: (0.82±0.48), t=2.69, P<0.05; NAA/Cr: (1.12±0.44), t=2.81, P<0.05)and the value of Cho/ Cr was increased in left hippocampus((2.49±0.78), t=2.36, P<0.05), but only the value of Glx/ Cr were reduced in right hippocampus((0.84±0.47), t=2.43, P<0.05), and the other metabolic indices changed unobvious.The depressive group had the significantly higher levels of IL-6, IL-2 in blood serum(IL-6: (12.47±3.19)ng/L, t=4.53, P<0.05; IL-2: (29.44±5.72)ng/L, t=2.44, P<0.05), but no significant difference was found in the IL-10 level in blood serum. The Glx/ Cr of bilateral hippocampus level was negatively correlated to the IL-6 and IL-2 level in blood serum(left: (IL-6: r=-0.555, P<0.05; IL-2: r=-0.624, P<0.05); right: (IL-6: r=-0.575, P<0.05; IL-2: r=-0.523, P<0.05)). The NAA/ Cr of left hippocampus level was negatively correlated to the IL-6 and IL-2 level in blood serum(IL-6: r=-0.582, P<0.05; IL-2: r=-0.607, P<0.05). The Cho/Cr of left hippocampus level was negatively correlated to the IL-6 and IL-2 level in blood serum(IL-6: r=0.601, P<0.05; IL-2: r=0.552, P<0.05). Conclusion The abnormal of glutamic acid system in bilateral hippocampus maybe the important performance and the potential originating link, the changes of the inflammatory cytokines level maybe the factor of these abnormal changes. Key words: Inflammatory cytokines; Magnetic Resonance Spectrum; First episode depression; Hippocampus