本實驗目的為探討大鼠短期餵予維生素A 補充飼料，對肝微粒體CYP3A 蛋白質含量的影響。採用平均體重為141.5 ±7.0公克的Wistar 公鼠12隻，先餵予A IN-76 生長飼料三週後的平均體重約為295.3±20.4公克。將動物隨機分成兩組，其中一組繼續餵予AIN-76 生長飼料(C組)，另一組則餵予維生素A 補充飼料(A 組，維生素A 含量為正常飼料的10倍)，飼養期為一週。大鼠終體重達到平均324 公克左右，各器官重量包含肝臟、腎臟•、肺臟、心臟、睪丸、脾臟等與副睪脂肪重量於兩組間皆無顯著差異•。肝臟視網醇(維生素A)濃度以A 組顯著增加，約為C組的2.8倍，但是血漿中的視網醇濃度於兩組問並無顯著差異。在肝微粒體細胞色素酵素蛋白質方面，不管是CYP3Al 或CYP3A2，其蛋白質表現含量於兩組間皆無顯著差異。從本實驗得知，十倍量維生素A 的補充飼料對動物體重與器官皆無不良影響，問時也不會顯著增加肝微粒體細胞色素酵素CYP3AI與CYP3A2 的蛋白質含量。 To study how the content of cytochrome P450 3A protein is affected by dietary vitamin A supplementation in short period , 12 male Wistar rats (142.5�7) were fed a control diet for 3 wk , and then randomly divided to 2 groups . The rats of 2 groups were fed with control diet (C group) and vitamin A supplemented diet ( A group ) separately for 1 wk. The final body weights of two groups were about 324g, and the organ weights ( liver , kidney , lung , heart , testis , spleen and epididymal fat pad included) showed no significant difference between the two groups . The A group showed significantly higher retinol concentration in liver at about 2.8 fold in that of C group. But plasma retinol between the two groups showed no significant difference. The CYP 3A protein levels in the liver microsome also showed no significant difference between the two groups. Thus , the vitamin A supplemented diet could increased the retinol concentration in rat liver but showed no effects on the protein levels of CYP3A1 or CYP3A2 in liver microsome of rats.