甲硝基亚硝胍和（或）雷尼替丁诱发大鼠腺胃粘膜肠上皮化生

Induction of Intestinal Metaplasia in the Glandular Stomach of Rats by N-Methyl-N-Nitro-N-Nitrosoguanidine and/or Ranitidine

分别采用含０．０３％雷尼替丁（Ｒ）的标准粉末状饲料、５０μｇ／ｍｌ甲硝基亚硝胍（ＭＮＮＧ）溶液及两者联合（ＭＮＮＧ＋Ｒ）喂饲大鼠共２０周，于实验第４３周末处死动物进行观察。ＭＮＮＧ＋Ｒ组腺胃粘膜肠上皮化生诱发率及平均肠化腺体数（１００．０％，６９６．２±１７３．６）显著地高于ＭＮＮＧ组（８６．５％，３３０．６±１４５．６）或Ｒ组（２２．５％、７５．２±３０．９）（Ｐ＜０．０１，Ｐ＜０．０５）；各组大鼠幽门腺区和胃底腺区粘膜表面ｐＨ值与肠化腺体数目之间呈显著的正相关（ｒ＝０．９６，ｒ＝０．９９）。结果表明ＭＮＮＧ＋Ｒ是建立大鼠腺胃粘膜肠化模型的一种理想方法；胃内高ｐＨ值可能是诱发胃粘膜肠上皮化生的主要因素之一；慢性胃病抗酸治疗的安全性还需进一步观察。

Either ranitidine (R) or N-methyl-N-nitro-N-nitrosoguanidine(MNNG) or both were administered to Wistar rats at a concentration of 0.03%in diet (R) or 50 μg/ml in drinking water(MNNG) ad libitum for 20 weeks. The rats were subsequently maintained without MNNG and/or R for an additional 23 weeks. An untreated control group was kept 43 weeks. Intestinal metaplasis (IM) was induced in the glandular stomachs of rats treated with MNNG(86.5%),R(22.5%),MNNG+R (100.0%)respectively while control group was 7.5%. There were highly significantly differences (P<0. 01,P<0. 05) between MNNG +R group and MNNG group,MNNG +R group and R group in the incidences of IM and sulphomucin positive IM, in the numbers of metaplastic glands, in pH value of gastric mucosa and its transmembranous potiential difference (PD);Apositive relation was observed between pH value of gastric mucosa and the number of metaplastic glarid (r=0. 99 in the fundic gland area, and r=0. 96 in the pyloric gland area). The results showed that :administration of both MNNG and R is a better method to induce IM of gastric mucosa in Wister rats;high pH value may be the one of main factos inducing IM of gastric mucosa;the safety of anti-acid therapy for chronic gastric diseases need to be further observed.