表研究以MNNG诱发了13例大白鼠胃平滑肌肉瘤。肿瘤原发于肌层,向胃外(7例)、胃壁内(3例)与胃腔内(3例)生长。均经HE、嗜银、VG、Masson’s三色与PTAH染色及电镜证实,低度恶性8例,高度恶性5例。其发生机理可能与MNNG浓度高、胃粘膜通透性增高、粘液细胞增生取代壁细胞致胃酸分泌减少,MNNG活性增强以及吐温加速MNNG溶解更易渗入肌层有关。 In the study, 13 cases of gastric leiomyosarcoma in rats were induced with MNNG. Tumors originated in the muscular layer and grew outward (in 7 cases), in the stomach (in 3 cases) and in the stomach (in 3 cases). All patients were confirmed by HE, argyrophil, VG, Masson’s trichrome and PTAH staining and electron microscopy. Eight cases were low grade and 5 cases were high grade. The mechanism may be related to the high concentration of MNNG, increased permeability of gastric mucosa, reduction of gastric acid secretion by mucus hyperplasia in place of parietal cells, increased MNNG activity, and Tween accelerate the dissolution of MNNG more easily into the muscularis.