Department of Otolaryngology-Head and Neck Surgery, the Second Affiliated Hospital, Chongqing University of Medical Sciences, Chongqing   400010, China

Li Fang★, Master, Department of Otolaryngology-Head and Neck Surgery, the Second Affiliated Hospital, Chongqing University of Medical Sciences, Chongqing   400010, China Fang L, Luo WL. Agmatine promotes expression of brain-derived neurotrophic factor in brainstem facial nucleus in the rat facial nerve injury model. Neural Regen Res 2008;3(6):618-20

Abstract

BACKGROUND: Studies have shown that agmatine can reduce inhibition of neuronal regeneration by increasing cyclic adenosine monophosphate and brain-derived neurotrophic factor (BDNF) in the hippocampus of morphine-dependent rats. The hypothesis that agmatine exerts similar effects on facial nerve injury deserves further analysis.

OBJECTIVE: To study the effects of peritoneal agmatine injection on BDNF levels in the rat brainstem after facial nerve injury.

DESIGN, TIME AND SETTING: A controlled animal experiment was performed at the Department of Otolaryngology-Head and Neck Surgery at the Second Affiliated Hospital, Chongqing University of Medical Sciences (Chongqing, China), between October and December in 2007.

MATERIALS: Twenty-four male Sprague-Dawley rats were randomly divided into a control, a lesion, and an agmatine treatment group, with eight rats in each group. Bilateral facial nerve anastomosis was induced in the lesion and agmatine treatment groups, while the control group remained untreated. A rat BDNF Enzyme-linked immunosorbent assay kit was used to measure BDNF levels in the brainstem facial nucleus.

METHODS: Starting on the day of lesion, the agmatine group received a peritoneal injection of 100 mg/kg agmatine, once per day, for a week, whereas rats in the lesion group received saline injections.

MAIN OUTCOME MEASURES: BDNF levels in the brainstem containing facial nucleus were measured by ELISA.

RESULTS: Twenty-four rats were included in the final analysis without any loss. Two weeks after lesion, BDNF levels were significantly higher in the lesion group than in the control group (P < 0.01). A significant increase was noted in the agmatine group compared to the lesion group (P < 0.01).

CONCLUSION: Agmatine can substantially increase BDNF levels in the rat brainstem after facial nerve injury.

Key Words: agmatine; facial nerve injury; brain-derived neurotrophic factor; ELISA

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