Campos F G, Waitzberg D L, Mucerino D R, Gonçalves E L, Logulo A F, Habr-Gama A, Rombeau J L
Surgical Technique Laboratory (Surgical Department), University of Sao Paulo Medical School, Brazil.
Nutr Hosp. 1996 May-Jun;11(3):167-77.
Radiotherapy plays an important role in cancer treatment, although it may cause collateral effects and sever complications due to cellular damage of peritumoral tissues. Recently different nutritional resources have been indicated to achieve intestinal protection during cancer irradiation. The aim of this study was to set the role of glutamine in acute actinic enteritis prevention. Sixty-five Wistar male rats (200 g) were maintained in individual metabolic cages, where body weight and food ingestion were carefully monitored daily. The animals were chosen at random in three groups and fed isocaloric and isoproteid diets: 1) CRt (23)-polymeric-casein diet (CD); 2) GRt (22)-polymeric-casein diet supplemented with 2% glutamine (GD), and 3) ERt (20)--elemental diet supplemented with 2% glutamine (ED). After an adaptation period (seven days), all rats received 1500 cGy of abdominal radiation in five equal daily doses of 300 cGy. After three days post radiation the rats were submitted to jejunal perfusion test with polyethylene-glicol 4000. Finally, small bowel and colon were resected for histological evaluation. It was observed that ERt group had greater average daily food intake than CRt and GRt groups during all periods (p < 0.05). All rats had equal weight gain during adaptation period; during irradiation all the animals had weight loss, but ERt group had smaller weight loss than CRt. All rats recovered weight after irradiation, and ERt group presented better results than the others (p < 0.05). Sodium transepithelial transport average values (mEq/min/cm) were negative and not statistically different in all groups. Small bowel histological evaluation in ERt and GRt rats were better than CRt rats, by preserving mucosal cellularity and increasing mitosis number and villi length (p < 0.05). Simultaneously, ERt group had greater number of rats with normal villuscrypt relation than CRt of CRt groups (p < 0.05). Large bowel histological data showed that the average crypt's length in ERt and GRt rats were greater than in CRt ones (p < 0.05). By the present work, an elemental diet enriched with 2% glutamine favored greater food ingestion and lessened weight loss during and after radiotherapy. Glutamine-supplemented polymeric or elemental diets given to rats before, during and after abdominal radiotherapy showed protective effects against radiation injury, by supporting mucosal structure and recovery.
放射疗法在癌症治疗中发挥着重要作用，尽管它可能会因肿瘤周围组织的细胞损伤而导致附带效应和严重并发症。最近，已表明不同的营养资源可在癌症放疗期间实现肠道保护。本研究的目的是确定谷氨酰胺在预防急性放射性肠炎中的作用。65只体重200克的雄性Wistar大鼠饲养在个体代谢笼中，每天仔细监测体重和食物摄入量。将动物随机分为三组，给予等热量和等蛋白饮食：1）CRt（23只）-聚合酪蛋白饮食（CD）；2）GRt（22只）-补充2%谷氨酰胺的聚合酪蛋白饮食（GD），以及3）ERt（20只）-补充2%谷氨酰胺的要素饮食（ED）。经过适应期（7天）后，所有大鼠接受1500 cGy的腹部辐射，分5次等量给予，每次300 cGy。辐射后3天，对大鼠进行聚乙二醇4000空肠灌注试验。最后，切除小肠和结肠进行组织学评估。观察到在所有时间段内，ERt组的平均每日食物摄入量均高于CRt组和GRt组（p<0.05）。在适应期所有大鼠体重增加相同；在辐射期间所有动物体重均减轻，但ERt组的体重减轻小于CRt组。所有大鼠在辐射后体重恢复，且ERt组的结果优于其他组（p<0.05）。所有组的钠跨上皮转运平均值（mEq/min/cm）均为负值，且无统计学差异。ERt组和GRt组大鼠的小肠组织学评估优于CRt组，表现为保留黏膜细胞数量、增加有丝分裂数和绒毛长度（p<0.05）。同时，ERt组具有正常绒毛-隐窝关系的大鼠数量多于CRt组（两组比较，p<0.05）。大肠组织学数据显示，ERt组和GRt组大鼠的隐窝平均长度大于CRt组（p<0.05）。通过本研究工作，富含2%谷氨酰胺的要素饮食有利于放疗期间及放疗后增加食物摄入量并减轻体重减轻。在腹部放疗前、放疗期间和放疗后给予大鼠补充谷氨酰胺的聚合或要素饮食，通过支持黏膜结构和恢复，对辐射损伤显示出保护作用。
