Abstract
Oral administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) to hamsters at a concentration of 50-83 μg/ml in the drinking water resulted in a high incidence of tumours in the glandular stomach. Short-term administration of MNNG for 4-6 months resulted in more adenocarcinomata in the glandular stomach than long-term administration for 7-8 months. One case of metastasis of an adenocarcinoma of the glandular stomach to the liver and 2 cases of metastasis to the regional lymph nodes were found. Spindle cell sarcomata in the glandular stomach and adenocarcinomata in the duodenum were also often produced.Oral administration of MNNG at the very high concentration of 500-2000 μg/ml induced a hepatic cell carcinoma, intrahepatic bile duct carcinomata, bile duct cystadenomata and cystic dilatation, and a haemangioma in the liver but no tumour in the glandular stomach.Sequential morphological studies on the glandular stomach of hamsters receiving 50 μg/ml of MNNG in the drinking water showed 3 stages of change of the mucosa. The mucosa became atrophic and eroded in the first 16 weeks. Irregular atypical glands developed at the margins of erosions and proliferation of spindle cells in the submucosa were found after 18 weeks. Spindle cell sarcomata developed in animals after 20 weeks. Adenocarcinomata developed between 25 and 32 weeks.
Highlights
methyl -N'-nitro -N-nitrosoguanidine (MNNG) for 4-6 months resulted in more adenocarcinomata in the glandular stomach than long-term administration for 7-8 months
All tumours were found in the vasion of differentiated adenocarcinoma upper alimentary tract except for one cells into the perineural lymphatics of the tumour each in an adrenal gland, the glandular stomach was found in one animal colon and a lymph node
As sum- (Fig. 4 and 5) and 2 other cases of poorly marized in the Table, 36 cases of carcinoma differentiated adenocarcinomata in Group and 79 cases of spindle cell sarcoma were 4 metastasized to the regional lymph nodes found among 117 cases of tumour of the where signet-ring type tumour cells were glandular stomach in these experiments. found (Fig. 6 and 7)
Summary
Effect of limited administration of MNNG at low concentration animals in Group 2, 2 in Group 4 and 1 in Group 5 developed a poorly differentiated adenocarcinoma. As sum- (Fig. 4 and 5) and 2 other cases of poorly marized, 36 cases of carcinoma differentiated adenocarcinomata in Group and 79 cases of spindle cell sarcoma were 4 metastasized to the regional lymph nodes found among 117 cases of tumour of the where signet-ring type tumour cells were glandular stomach in these experiments. The percentages of adenocarcinomata a spindle cell sarcoma to a regional lymph among the total tumours produced in the node was found in one animal in Group 2. 2.-Neoplastic signet-ring cells infiltrating the muscularis propria of the pyloric region of the glandular stomach. . i tSTOMACHTUMOURSINHAMSTERS # ....s. v .E. Fia. 7.-Poorly differentiated adenocarcinoma of the signet-ring cell type shown in Fig. 6 metastasized to a regional lymph node.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
