维生素B12混合液灌胃对放射性肠炎模型大鼠的治疗作用及机制

目的：探讨维生素B12灌胃对放射性肠炎大鼠的治疗作用及机制.方法：将30只雄性SD大鼠随机分为3组,正常对照组（A组）、10Gy剂量照射后给予蒸馏水灌胃处理组（B组）,10Gy剂量照射后给予维生素B12混合液灌胃处理组（C组）,B、C两组连续灌胃5d,采用免疫组织化学SP法染色,在光镜下观察肠腺上皮细胞增殖核抗原（PCNA）的表达,ELISA检测肠组织TNF-α的表达,硝酸还原酶法检测肠组织NO的表达.结果：C组大鼠的肠上皮PCNA阳性细胞数明显多于B组大鼠（P＜0.05）,少于A组大鼠,C组大鼠肠组织的TNF-α、NO的含量明显少于B组模型大鼠（P＜0.05）,多于A组大鼠.结论：VB12混合液可促进急性放射肠炎大鼠直肠上皮细胞的增殖,降低肠组织TNF-α、NO的含量.

The Therapeutical Effects of Gavage with Vitamin B12 Mixed Solution on Radiation Enteritis Model Rats and Its Mechanism

Objective： To investigate the therapeutical effects of vitamin B12 （VB12） mixed solution on acute radiation enteritis rats and its mechanisms. Methods： Thirty male SD rats were randomly di- vided into three groups. Group A： normal control group, group B： the rats accepted 10Gy radiation and were given distilled water by gavage for 5 days, group C： after accepted 10Gy radiation the rats were given VB12 mixed solution by gavage for 5 days. Immunohistochemistry S-P method was used to detect the expression of proliferating cell nuclear antigen （PCNA） in intestinal epithelial cell. The ex- pression of tumor necrosis factor alpha （TNF-c~） in intestinal tissue was measured by ELISA and nitric oxide （NO） levels were measured by nitric reductases. Results： PCNA positive cells in group C were more than in group B and less than in group A （ P 〈 0.05 ） ; The levels of TNF-eL and NO in group C were lower than those in group B and higher than in group A（P 〈0.05）. Conclusions： VB12 mixed solution can improve the proliferation of intestinal epithelial cells of acute radiation enteritis rats and decrease TNF-α and NO levels.