Birt D F, Hines L A
Drug Nutr Interact. 1982;1(2):143-51.
Male Syrian hamsters consumed one of three levels of lactalbumin (10, 20, or 40%) for 8 weeks prior to administration of a single dose of 20 mg/kg (sc) N-nitrosobis(2-oxopropyl)amine (BOP) at 0600 hr. Liver weights, liver microsomal protein, and cytochrome P450 content and the activities of microsomal ethylmorphine N-demethylase (EMND), aniline hydroxylase (ANH), and arylhydrocarbon hydroxylase (AHH) were determined in control and BOP-treated animals after 0 (0600), 3 (0900), 6 (1200), 12 (1800), and 24 (0600) hr. Circadian rhythms were observed in liver weights, contents of microsomal protein, and cytochrome P450 and in the activities of EMND and ANH. Cycles of liver weight, cytochrome P450, and EMND activity were present in animals fed the higher (20 and 40%) lactalbumin levels, but not in those fed the low level (10%). BOP treatment eliminated the circadian cycles of cytochrome P450 and EMND, and reduced liver weight, the content of microsomal protein, and the ANH activity at two or three of the measurement times. AHH activity did not exhibit a circadian cycle, but these values were consistently increased by feeding high protein and reduced by BOP.
雄性叙利亚仓鼠在上午06:00单次皮下注射20 mg/kg N-亚硝基双(2-氧代丙基)胺(BOP)之前8周，食用三种水平（10%、20%或40%）的乳白蛋白之一。在0（06:00）、3（09:00）、6（12:00）、12（18:00）和24（06:00）小时后，测定对照动物和经BOP处理的动物的肝脏重量、肝脏微粒体蛋白、细胞色素P450含量以及微粒体N-脱甲基酶（EMND）、苯胺羟化酶（ANH）和芳烃羟化酶（AHH）的活性。观察到肝脏重量、微粒体蛋白含量、细胞色素P450以及EMND和ANH活性存在昼夜节律。在喂食较高（20%和40%）乳白蛋白水平的动物中存在肝脏重量、细胞色素P450和EMND活性的周期，但在喂食低水平（10%）的动物中不存在。BOP处理消除了细胞色素P450和EMND的昼夜周期，并在两到三个测量时间点降低了肝脏重量、微粒体蛋白含量和ANH活性。AHH活性未表现出昼夜周期，但通过喂食高蛋白这些值持续增加，而BOP使其降低。
