Rush G F, Maita K, Sleight S D, Hook J B
Proc Soc Exp Biol Med. 1983 Apr;172(4):430-9. doi: 10.3181/00379727-172-41583.
Administration of phenobarbital (60 mg/kg) daily for 4 days to male rabbits resulted in induction of renal cytochrome P-450 (3.5-fold) and a corresponding increase in ethoxycoumarin-O-deethylase and benzphetamine-N-demethylase activity (17- and 4-fold, respectively). Kidney weight to body weight ratio and renal ethoxyresorufin-O-deethylase were not affected by phenobarbital pretreatment. Numerous focal areas of proliferation of smooth endoplasmic reticulum (SER) were evident in proximal tubule cells from phenobarbital treated rabbits while proximal tubular cells from control rabbits had only small and sparcely located aggregates of SER. Phenobarbital-induced SER proliferation was specifically localized to the S3 segment of the proximal tubule. Proliferation was not observed in S2 cells of the proximal tubule, cells of Henle's loop, distal tubules, or collecting tubules in rabbits pretreated with phenobarbital. These data demonstrate the biochemical heterogeneity of cell types within the proximal tubules of rabbits. Furthermore, induction of mixed-function oxidases specifically in S3 cells of the proximal tubule may be of toxicological significance in the metabolic activation of certain nephrotoxicants.
对雄性兔子每日给予苯巴比妥（60毫克/千克），持续4天，可诱导肾脏细胞色素P - 450（增至3.5倍），并相应增加乙氧香豆素 - O - 脱乙基酶和苄非他明 - N - 脱甲基酶活性（分别增至17倍和4倍）。苯巴比妥预处理对肾脏重量与体重之比以及肾脏乙氧试卤灵 - O - 脱乙基酶没有影响。在经苯巴比妥处理的兔子的近端小管细胞中，可见许多光滑内质网（SER）增殖的局灶性区域，而对照兔子的近端小管细胞仅有少量且分布稀疏的SER聚集体。苯巴比妥诱导的SER增殖特异性地定位于近端小管的S3段。在用苯巴比妥预处理的兔子中，未在近端小管的S2细胞、髓袢细胞、远端小管或集合小管中观察到增殖。这些数据证明了兔子近端小管内细胞类型的生化异质性。此外，在近端小管的S3细胞中特异性诱导混合功能氧化酶可能对某些肾毒物的代谢活化具有毒理学意义。
