비타민C 및 비타민A가 Hamster 협점막의 9, 10-dimethyl-1, 2-benzanthracene(DMBA) 유도 구강암에 미치는 영향에 관한 실험적 연구

AN EXPERIMENTAL STUDY ON THE EFFECTS OF VITAMIN C AND A OF THE ORAL TUMORS OF HAMSTER BUCCAL POUCH INDUCED BY 9, 10-DIMENTHYL-1, 2-BENZANTHRACENE(DMBA)

This study was undertaken to observe the inhibitory effects of vitamin C and A of the oral tumors of hamster buccal pouch induced by 9,10-dimethyl-1,2-benzanthracene. 96 of Golden syrian hamsters, weighing about 100 grams, were used for this experimental study and divided into normal (6), control (18), and experimental (72) groups. Only heavy mineral oil was painted on right buccal pouch of control group (18). One part of experimental group (24) was applied 0.5% DMBA in heavy mineral oil mainly and the other experimental groups (24, 24) were applied vitamin C & A plus 0.5% DMBA in heavy mineral oil respectively. All animals were sacrified on the 6th, 8th, 10th, 12th, 14th, and 16th week serially. The buccal pouch tissues were excised, examined grossly, lightmicroscopically, and electromicroscopically. SDS-polyacrylamide gel electrophoresis was also performed in order to analyse tumorspecific protein changes in this experimental study. Following results were obtained from this study: 1. In experimental Group Ⅰ, hyperkeratosis and dysplasia in the 6th week, acanthosis in th 8th week, papilloma in the 10th week, carcinoma in situ in 14th week, and carcinoma in situ or invasive carcinoma in the 15th week were observed microscopically. 2. In experimental Group Ⅱ, hyperkeratosis and acanthosis in the 8th week, and dysplasia and papilloma were observed from the 10th week, but carcinoma in situ and invasive carcinoma were not able to observed during the experimental period. 3. In experimental GroupⅢ, hyperkeratosis in the 6th week, dysplasia and acanthosis in the 8th week, and papilloma and carcinoma in situ in 14th week were observed microscopically. 4. Electromicroscopically, irregular nucleoli, enlargement of intercellular space, extension of cytoplasmic process and breakage of basement membrane were observed during the carcinogenesis. But minimal breakage of basement membrane in 16th week of experimental Group Ⅱ and minimal enlargement of intercellular space and decrease of tonofilaments in the 8th and 10th week of experimental Group Ⅲ were observed. 5. In the result of eletrophoresis, decrease of 93K, 50.5K, 39.4K, and 35.3K soluble protein and increase of 46K surface protein were observed in all experimental group. 6. In the result of electrophoresis, loss of 46K soluble protein, increase of 61.2K, and decrease of 57.8K surface protein were observed in experimental Group Ⅱ and Ⅲ but not in experimental Group Ⅰ. From this study, author suggests that there was a tendency of tumor-inhibitory effects of vitamin C and A due to synthesis of collagen and basement membrane, maintenance of intercellular space and inhibition of cellular proliferation, and changes of tumor-specific and tumor-inhibitory polypeptides were presented on experimental carcinogenesis of buccal pouch. Author should like to give an advice on the purification and biologic effects of tunor-specific and tunor-inhibitory polypeptides made on further study.