Retinyl Acetate가 白鼠 乳房癌 發生에 미치는 影響에 對한 硏究 = An Experimental Study of the Effects of Retinyl Acetate on Mammary Carcinogenesis in Sprague-Dawley Rats

다국어 초록 (Multilingual Abstract)

An experimental study was performed to study the effects of retinyl acetate on N-methyl-N-nitrosourea induced mammary carcinogenesis in Sprague-Dawley rats. Female Sprague Dawley rats were given an intravenuous injection of 5 mg of N-methyl-N-nitrosoureaper 100 gm body weight at 60 and 67 days of age, respectively. After carcinogenic treatment, feeding of a diet supplemented 1/2 mmol (164 mg) or 1mmol (328 mg) retinyl acetate per kilogram diet was irritated from the day of carcinogenic treatment. During the experiment the animals were checked biweekly for the detection of mammary tumors. Thus, the incidence of tumors, the trend and numbers of tumor occurrence, changes of body weight, and the size of tumor were evaluated.
The results were follows:
1. Tumor incidence in the NMU treated group with control diet was 46.7%, 33.3% in the group with 1/2 mmol retinyl acetate, and 13.3% in the group with 1 mmol retinyl acetate supplied group compared with the NMU-only treated group.
2. Tumors occurred between 14th and 16th week after injection of NMU. The number of tumors was not significantly different between the NMU-only treated group and the 1/2 mmol retinyl acetate supplied group. There was, however, a significant difference in the 1 mmol retinyl acetate supplemented group compared to the NMU-only treated group.
3. Body weights of the animals gradually increased during the experiments and there was no statistical difference among the groups.
4. The average size of the tumors was 3.9cm in the NMU-only treated group, 3.93cm in the 1/2 mmol retinyl acetate group, and 4.63cm in the 1 mmol retinyl acetate group. Histologic features of the tumors were identical in the experimental groups.