谷氨酰胺对放射性口腔黏膜炎的营养防护作用

Effects of glutamine on nutritional therapy of radiation-induced oral mucositis

放射性口腔黏膜炎是头颈肿瘤放射治疗中最常见的并发症,主要表现为口腔疼痛、吞咽困难、进食减少以及继发性感染,严重时可导致治疗中断,影响治疗疗效和生活质量。但到目前为止,放射性口腔黏膜炎的临床管理尚无标准治疗方法,以预防、镇痛及营养补充等对症治疗为主。近年来,谷氨酰胺作为一种免疫营养物质,成为防治放射性口腔黏膜炎的研究热点,在国内外指南中均有提及,目前处于强共识但缺乏强证据的阶段。谷氨酰胺为非必需氨基酸,在人体游离氨基酸池中含量最为丰富。机体功能正常时,肝脏和骨骼肌是合成及储存谷氨酰胺的主要器官,而脑组织、黏膜、免疫细胞等是消耗谷氨酰胺的主要场所。肿瘤患者处于营养物质高分解代谢状态,对谷氨酰胺的需求增加,但合成减少,黏膜和免疫细胞无法及时补充谷氨酰胺,可能会对放射性口腔黏膜炎的防治产生负面影响。本文针对放射性黏膜损伤的病理生理机制、谷氨酰胺可能作用的靶点以及相关临床研究与应用进行综述,以期为临床提供参考。

Radiation-induced oral mucositis is the most common complication of radiotherapy for head and neck neoplasms.The relevant symptoms include oral pain dysphagia decreased diet intake and secondary infection which can lead to the interruption of treatment and even affect the clinical efficacy and quality of life.But so far there has been no effective treatment for the clinical management of radiation-induced oral mucositis and the treatment of patients with prevention pain and nutrition is mainly supported by treatment.In recent years glutamine as a kind of immunonutrient substance has become a research hotspot in the prevention of radiation-induced oral mucositis and has been mentioned in the guidelines of various countries which is currently in a stage of strong consensus but absence of abundant evidence.In terms of Nutriology glutamine is a non-essential amino acid and the most abundant free amino acid in the human body.In normal functioning the liver and skeletal muscle are the major organs that synthesize and store glutamine.While the main sites of glutamine consumption are brain tissue mucosa immune cells etc.Cancer patients are in a state of high catabolism of nutrients with an increased demand for glutamine but a decreased synthesis.Glutamine can not be timely replenished to the mucosa and immune cells which may have a negative impact on the prevention and treatment of radiation-induced oral mucositis.Based on current researches on radiotherapy—induced mucosal injury and the repair of glutamine on wound healing pathophysiology the mechanism of glutamine clinical research and application for radiotherapy—induced mucosal injury were reviewed aiming to provide references for clinical practice.