维生素D_3对大鼠胃腺癌作用的研究

方法：经饮水摄入Ｎ－甲基－Ｎ′－亚硝基－Ｎ－亚硝胍（ＭＮＮＧ，１５０ｍｇＬ－１）制作大鼠胃腺癌模型，饲以１，２５－二羟基维生素Ｄ３〔１，２５（ＯＨ）２Ｄ３〕添加的饲料（２．５ｍｇｋｇ－１和５．０ｍｇｋｇ－１）。于实验１６、３２周处死动物，进行增生细胞核抗原（ＰＣ－ＮＡ）免疫组织化学和组织病理学研究。结果：实验１６周，１，２５（ＯＨ）２Ｄ３（５．０ｍｇｋｇ－１）添加组大鼠腺胃粘膜上皮细胞ＰＣＮＡ标记率明显高于只经饮水摄入ＭＮＮＧ组，实验３２周胃腺癌发生率、癌巢数和微血管密度显著增加。结论：一定剂量的１，２５（ＯＨ）２Ｄ３对ＭＮＮＧ诱发大鼠胃腺癌的发生有促进作用。

TX EFFECT OF 1,25 DIHYDROXYVITAMIN D3 ON GASTRIC CARINOGENESIS INDUCED BY N-METHYL-N′-NITRO-N-NITROSOGUANIDINE IN RATS

The　effect　of　1,25 dihydroxyvitamin　D3〔1,25(OH)2D3〕　on　gastric　carcinogenesis　induced　by　N methyl N′ nitro N nitrosoguanidine　(MNNG)　was　investigated　in　male　Wistar　rats.In　rats,gastric　carcinogenesis　was　induced　by　MNNG(150mg·L-1)　in　drinking　water.Four　weeks　after　MNNG　exposure,the　rats　were　fed　with　diet　containing　1,25(OH)2D325mg·kg-1　and　5.0　mg·kg-1　respectively　and　maintained　the　MNNG　drinking　water.The　animals　were　killed　by　the　16th　and　32th　week　for　immunohistochemical　and　histopathological　studies.Supplementation　of　1,25(OH)2D3(5.0mg·kg-1)in　the　diet　caused　dramatic　increase　in　proliferating　cell　nuclear　antigen　labelling　index　in　epithelium　of　glandular　stomach　of　rats　receiving　MNNG　by　the　16th　week.By　the　32th　week,adenocarcinoma　incidence,number　of　individual　cancer　foci　and　microvessel　density　in　glandular　stomach　of　rats　receiving　1,25(OH)2D3(5.0mg·kg-1)　and　MNNG　were　significantly　higher　than　that　receiving　MNNG　alone.It　was　concluded　that　certain　dose　of　1,25(OH)2D3　stimulated　gastric　carcinogenesis　induced　by　MNNG　in　rats.