In the present study, the antidepressant effects of L-arginine in a rat model of chronic mild stress-induced depression were investigated. Animals were divided into group I (sham), group II (control, depression), group III (10 mg/kg L-arginine), group IV (20 mg/kg L-arginine), and group V (10 mg/kg venlafaxine, positive control). The doses were orally administered for 30 consecutive days. Sucrose preference analysis as well as forced swim and open field tests were performed. Serum cortisol, nitric oxide (NO), and monoamine levels in brain tissue were then measured. Brain-derived neurotrophic factor (BDNF) expression was also examined. Supplementation with L-arginine significantly increased the sucrose preference ratio, locomotor activity, and monoamines and decreased serum cortisol and NO levels. The mRNA and protein expression of BDNF in the brain tissue was significantly reduced (>50%) in control rats. However, supplementation with L-arginine significantly increased BDNF mRNA expression (>50%) in both groups. Similarly, increased BDNF protein expression after L-arginine treatment was confirmed using Western blot and immunohistochemical analyses. In conclusion, L-arginine supplementation may be effective against chronic stress-induced depression.

中文翻译：

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L-精氨酸通过增加大鼠脑源性神经营养因子的表达，对慢性轻度应激诱导的抑郁症具有抗抑郁作用。

在本研究中，研究了L-精氨酸在慢性轻度应激诱导的抑郁症大鼠模型中的抗抑郁作用。将动物分为I组（假），II组（对照，抑郁症），III组（10mg / kg L-精氨酸），IV组（20mg / kg L-精氨酸）和V组（10mg / kg）。文拉法辛，阳性对照）。连续30天口服给药。进行了蔗糖偏爱分析以及强迫游泳和野外测试。然后测量脑组织中的血清皮质醇，一氧化氮（NO）和单胺水平。还检查了脑源性神经营养因子（BDNF）的表达。补充L-精氨酸可显着提高蔗糖偏爱率，运动活性和单胺，并降低血清皮质醇和NO水平。对照大鼠脑组织中BDNF的mRNA和蛋白表达显着降低（> 50％）。然而，在两组中补充L-精氨酸均显着增加了BDNF mRNA表达（> 50％）。类似地，使用蛋白质印迹和免疫组织化学分析证实了L-精氨酸处理后BDNF蛋白表达增加。总之，补充L-精氨酸可能有效预防慢性应激引起的抑郁。