目的探讨minocycline抑制炎症反应对血管性抑郁小鼠行为及神经递质的影响。 方法成年雄性CD1小鼠随机分为3组，每组各10只，实验组造模后立即腹腔注射minocycline每日1次连续7 d（30 mg/kg），对照组造模后给予同等剂量的生理盐水，假手术组除不阻断颈动脉供血外，其余手术操作与实验组相同，术后同样给予腹腔注射相应剂量的生理盐水。术后第8天起行悬尾实验（第8天）、旷场实验（第9天）检测抑郁行为，水迷宫定向航行实验（第10天）检测认知能力。术后第11天处死取脑，分离海马匀浆，酶联免疫吸附测定（enzyme-linked immunosorbent assay，ELISA）试剂盒检测肿瘤坏死因子-α（tumor necrosis factor α，TNF-α）、白细胞介素-1β（interleukin-1β，IL-1β）及白细胞介素-6（interleukin-6，IL-6）含量，并通过高效液相色谱法（high performance liquid chromatography，HPLC）对抑郁相关的单胺类神经递质进行检测，包括5-羟色胺（5-hydroxytryptamine，5-HT）、去甲肾上腺素（norepinephrine，NE）及多巴胺（dopamine，DA）。 结果3组小鼠悬尾实验不动时间差异有显著性[实验组：（174.75±11.37）s，对照组：（194.32±14.32）s，假手术组：（169.62±19.27）s，F=6.59，P=0.005]；与对照组相比，实验组和假手术组悬尾不动时间显著缩短；3组小鼠探洞次数、活动时间、活动路程差异显著（F=6.17，P=0.008；F=11.55，P＜0.001；F=13.47，P＜0.001）；与对照组相比，实验组与假手术组探洞次数明显增多[实验组：（50.86±9.23）次，对照组：（35.73±11.96）次，假手术组：（48.14±10.16）次]，活动时间与活动总路程均明显延长[实验组：（786.70±27.51）s，对照组：（738.88±36.00）s，假手术组：（807.90±33.16）s；实验组：（37171.42±8493.40）mm，对照组：（28992.91±5760.03）mm，假手术组：（47206.23±8219.84）mm]；水迷宫实验潜伏期差异有显著性[实验组：（87.38±13.36）s，对照组：（88.50±19.88）s，假手术组：（44.38±19.76）s，F=16.09，P＜0.001]，与假手术组相比，实验组和对照组潜伏期显著延长。炎症因子检测提示，3组海马TNF-α、IL-1β及IL-6差异具有显著性[实验组：（141.10±24.36）pg/100 mg，对照组：（167.6±15.91）pg/100 mg，假手术组：（123.8±15.53） pg/100 mg，F=13.42，P＜0.001；实验组：（5.32±1.89）pg/mg，对照组：（10.31±2.83）pg/mg，假手术组：（4.50±2.07）pg/mg，F=18.69，P＜0.001；实验组：（20.01±3.62）pg/mg，对照组：（24.39±5.04）pg/mg，假手术组：（18.40±3.78）pg/mg，F=5.49，P=0.010]；与对照组相比，实验组与假手术组3种炎性细胞因子均显著降低。3组海马5-HT及DA含量差异有显著[实验组：（3.89±1.21）ng/ml，对照组：（3.13±1.44）ng/ml，假手术组：（5.01±1.68）ng/ml，F=4.17，P=0.026；实验组：（10.72±2.65）ng/ml，对照组：（7.99±2.31）ng/ml，假手术组：（11.76±3.10）ng/ml，F=5.18，P=0.012]；与对照组相比，实验组和假手术组DA含量显著增加，实验组5-HT含量差异无显著性，而假手术组5-HT含量增多；3组NE含量差异无显著性[实验组：（3.97±1.35）ng/ml，对照组：（3.16±1.55）ng/ml，假手术组：（4.68±1.99）ng/ml，F=2.13，P=0.139]。 结论 Minocycline能够抑制血管性抑郁小鼠炎症因子的表达，抗炎症治疗可改善其抑郁行为，对认知损害未观察到明显改善，相关的神经递质以DA的改变为最明显。%Objective To investigate the effects of minocycline, a neuroinflammation inhibitor, on the depressive behaviors and neurotransmitters in the vascular depression mice model. Methods Male CD1 mice were subject to repeated common carotid artery occlusion and reperfusion to establish the vascular depression model, then randomly divided into experimental group (n=10), control group (n=10) and sham group (n=10). Minocycline (30 mg/kg, i.p.) and same dose of saline were administrated immediately after the surgery and subsequently the consecutive 6 days in experimental group and control group respectively. Mice in sham group were conducted the same surgery expect occluding carotid artery, then administered the same dose of saline as the control group. After the administration, tail suspension test and open-ifeld test were used to assess depression behaviors of mice on the post operation day (POD) 8 and 9 respectively, and Morris water maze was used to assess cognitive function on the POD 10. On POD 11, mice were deeply anesthetized and euthanized and transcardially perfused with phosphate buffered saline (PBS). Expressions of tumor necrosis factor α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6) in hippocampus were measured by enzyme-linked immunosorbent assay (ELISA) kit. Contents of 5-hydroxytryptamine (5-HT), norepinephrine (NE) and dopamine (DA) were measured by high performance liquid chromatography (HPLC). Results Among the three groups, the immobility time was signiifcantly different ([174.75±11.37]s vs [194.32±14.32]s vs [169.62±19.27]s, F=6.59, P=0.005), and the immobility time of experimental group and sham group was shorter than control group significantly. The times of exploring holes, prolonged time and distance of movement were signiifcantly different (F=6.17, P=0.008;F=11.55, P<0.001;F=13.47, P<0.001), the times of exploring holes of experimental group and sham group was more than control group signiifcantly, and so did both prolonged time and distance of movement of those two groups. But there was significant difference in escape latency ([87.38±13.36]s vs [88.50±19.88]s vs [44.38±19.76]s, F=16.09, P<0.001) among the three groups, the escape latency of experimental group and control group was signiifcantly longer than sham group. The expression of TNF-α, IL-1βand IL-6 in hippocampus were down-regulated in experimental group and sham group compared with control group (TNF-α:[141.10±24.36]pg/100 mg vs [167.6±15.91]pg/100 mg vs [123.8±15.53]pg/100 mg, F=13.42, P<0.001;IL-6:[20.01±3.62]pg/mg vs [24.39±5.04]pg/mg vs [18.40±3.78]pg/mg, F=5.49, P=0.010;IL-1β([5.32±1.89]pg/mg vs [10.31±2.83]pg/mg vs [4.50±2.07] pg/mg, F=18.69, P<0.001). There were no signiifcant difference in the level of NE among the three groups ([3.97±1.35]ng/ml vs [3.16±1.55]ng/ml vs [4.68±1.99]ng/ml, F=2.13, P=0.139), but there is a increased level of DA in experimental group and sham group compared with control group ([10.72±2.65] ng/ml, [11.76±3.10] ng/ml vs [7.99±2.31] ng/ml). Conclusion Minocycline can restrain the expression of inflammatory cytokines in vascular depression mice, and inhibited inflammation may improve their depression behaviors, but no improvement found in the cognitive impairment. Among those relevant neurotransmitters, the content of DA changes most signiifcantly.
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