旋转磁场对大鼠放射性食管炎的防治作用

The effects of a rotating magnetic field in the prevention and treatment of irradiation-induced esophagitis

目的观察旋转磁场对急性放射性食管炎模型大鼠的防治作用。方法根据随机数字表法将40只雌性Wistar大鼠随机分为正常对照组（对照组）、辐射组、氨磷汀治疗组（氨磷汀组）、90min磁场治疗组（90min磁场组）和120rain磁场治疗组（120min磁场组）五组，每组8只。除对照组外，其余4组用6MVX线直线加速器对大鼠食管上段3（~ITI单次照射43Gy制作放射性食管炎模型。每组分别于照射后第7天和第14天两个时间点，各取4只大鼠进行活体观察和取材：取腹主动脉血检测血常规和细胞因子水平；取全长食管组织，常规石蜡包埋，切片，经HE染色，光镜下观察病理改变。结果辐射组大鼠食管组织于照射后第7天出现放射性食管炎改变，食管黏膜上皮坏死脱落，黏膜下层充血、水肿，并伴有大量炎症细胞浸润；照射后第14天病理改变与第7天相似。氨磷汀组、90min磁场组和120min磁场组大鼠食管组织放射性炎症反应较轻，且照射后第14天黏膜鳞状上皮有修复倾向，血常规检查发现白细胞和中性粒细胞数明显低于辐射组（P〈0．05）；而90min磁场组和120rain磁场组大鼠血清肿瘤坏死因子-a（TNF-a）、白细胞介素-1（IL-1）和白细胞介素-6（IL-6）均较辐射组低（P〈0．05）。结论旋转磁场和氨磷汀对大鼠放射性食管炎均有较好的防治作用，疗效相近；旋转磁场可抑制致炎因子的表达，减轻食管组织的急性放射性炎症反应。

Objective To observe the effect of a rotating magnetic field in preventing and treating irradiation-induced esophagitis in rats. Methods Forty female Wistar rats were randomized into 5 groups： a non-irradiated control group, an irradiation group, an amifostine treatment group （ amifostine group） , a 90 rain magnetic field treatment group （90 rain magnetic group） and a 120 min magnetic field treatment group （120 min magnetic group） , with 8 rats in each group. The esophaguses of all rats except those in the control group were exposed to a single irradi- ation with 6 MV X-rays from a linear accelerator at a dosage of 43 Gy. Four rats in each group were randomly chosen to be observed 1 and 2 weeks after the irradiation. Blood cytokines were detected in their arterial blood. Any pathological changes of the esophagus were observed with HE staining under a light microscope at the same time. Results Irradiation-induced esophagitis was observed in the irradiation group 7 days after irradiation, with obvious exfoliation and necrosis of the esophagal epithelium mucosae. The submucosa were hyperaemie and dropsical with abundant in- flammatory cell infiltration. The pathological changes of the esophagus were similar at 7 and 14 days after irradiation. However, the irradiation-induced esophagitis of rats in the amifostine group, the 90 min magnetic group and the 120 min magnetic group were relatively slighter and the blood leucocytes and neutrophis in those 3 groups were signifi- cantly lower than those in the irradiation group, while a tendency toward repair of the mucosa of the esophagus was detected. Serum TNF-a, IL-1 and IL-6 in the 90 min magnetic group and 120 min magnetic group were significantly lower than those in the irradiation group. Conclusions Both a rotating magnetic field and amifostine can help prevent and treat irradiation-induced esophagitis. Their therapeutic efficacy is similar. Exposure to a rotating magnetic field could inhibit the expression of inflammatory factors, and thus lessen the inflammatory reaction of acute irradiation-induced esophagitis.