Mak K M, Leo M A, Lieber C S
Trans Assoc Am Physicians. 1984;97:210-21.
The effect of ethanol consumption on the development of squamous metaplasia of the trachea caused by vitamin A deficiency was studied in rats fed for 8-14 weeks with either normal vitamin A-containing diets or diets lacking vitamin A. Littermates were pair-fed the same diets with carbohydrates (36% of energy) replaced by ethanol. In rats fed the normal vitamin A diet with or without ethanol the tracheal mucosa was lined by a pseudostratified ciliated columnar epithelium; no squamous metaplasia was observed. Serum vitamin A was normal in both groups. Squamous metaplasia was noted in 4 of 7 rats fed the vitamin A-free diet and in 6 of 7 animals fed the vitamin A-free diet plus ethanol; the lesions were present in 48 and 68% of all the sections, respectively. Furthermore, the most severe lesions were seen only in the vitamin A-free diet plus ethanol group. Serum vitamin A was low in both groups. Ethanol consumption also results in lysosomal and ciliary abnormalities in the ciliated cells of the tracheal epithelia that were not as yet involved in the formation of squamous metaplasia. Thus, these synergistic effects of vitamin A deficiency and ethanol could contribute to the enhanced incidence of respiratory cancer seen in the alcoholic.
研究了乙醇摄入对维生素A缺乏所致大鼠气管鳞状化生发展的影响。给大鼠喂食含正常维生素A的饲料或缺乏维生素A的饲料8 - 14周。同窝出生的大鼠成对喂食相同的饲料，其中碳水化合物（占能量的36%）被乙醇替代。在喂食含或不含乙醇的正常维生素A饲料的大鼠中，气管黏膜由假复层纤毛柱状上皮覆盖；未观察到鳞状化生。两组大鼠的血清维生素A均正常。在喂食不含维生素A饲料的7只大鼠中，有4只出现鳞状化生；在喂食不含维生素A饲料加乙醇的7只动物中，有6只出现鳞状化生；病变分别出现在所有切片的48%和68%中。此外，最严重的病变仅见于不含维生素A饲料加乙醇组。两组大鼠的血清维生素A均较低。乙醇摄入还导致气管上皮纤毛细胞出现溶酶体和纤毛异常，这些细胞尚未参与鳞状化生的形成。因此，维生素A缺乏和乙醇的这些协同作用可能导致酒精中毒者呼吸道癌症发病率增加。
