Heterogeneous expression of phenobarbital-inducible cytochrome P-450 genes within the hepatic acinus in the rat.
Heterogeneous expression of phenobarbital-inducible cytochrome P-450 genes within the hepatic acinus in the rat.
复制标题
大鼠肝腺泡内苯巴比妥诱导的细胞色素 P-450 基因的异质表达。
DOI：
10.1002/hep.1840060522
复制
发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Gumucio,JJ
中科院分区：
文献类型：
--
作者：
Chianale,J;Dvorak,C;May,M;Gumucio,JJ
在肝腺泡（肝实质的功能单位）内，苯巴比妥对细胞色素P-450蛋白的诱导主要表现在靠近肝小静脉的肝细胞中，即远端肝细胞。本研究的目的是确定细胞色素P-450 b和P-450 e mRNA的水平在人口中的肝细胞起源于近端或远端一半的肝腺泡在大鼠，作为一种方法来阐明的机制，负责细胞色素P-450蛋白的异质性区域表达。开发一种新的方法来分离肝细胞起源于肝腺泡的近端或远端的一半，使总细胞色素P-450含量和细胞色素P-450 b和P-450 e的mRNA在这些肝细胞的测量。细胞色素P-450 b和P-450 e mRNA水平在近端和远端肝细胞中通过聚（A+）RNA与这两种细胞色素的cDNA识别序列的北方印迹杂交进行评估。通过在单次苯巴比妥注射后测量这些参数来定义诱导动力学。细胞色素P-450 mRNA水平在16小时达到最大诱导，48小时恢复到基础值。相反，总细胞色素P-450微粒体蛋白含量达到最大诱导后33 hr. Hepatocytes的肝腺泡的远侧一半的苯巴比妥与细胞色素P-450 b和P-450 e mRNA水平高于近端肝细胞。这些结果表明，有调制的细胞色素P-450 b和P-450 e基因的表达在肝腺泡。
Within the hepatic acinus, the functional unit of liver parenchyma, the induction of cytochrome P-450 protein by phenobarbital is manifested primarily in hepatocytes located closer to the hepatic venule, ie, distal hepatocytes. The objective of this study was to determine the levels of cytochromes P-450b and P-450e mRNAs in populations of hepatocytes originating in the proximal or distal half of the liver acinus in the rat, as an approach to the elucidation of the mechanisms responsible for the heterogeneous zonal expression of cytochrome P-450 protein. The development of a new method to isolate hepatocytes originating from the proximal or distal half of the liver acinus enabled the measurement of total cytochrome P-450 content and of cytochromes P-450b and P-450e mRNAs in these hepatocytes. Levels of cytochromes P-450b and P-450e mRNAs were assessed in proximal and distal hepatocytes by Northern blot hybridization of poly (A+) RNA with a cDNA recognizing sequences of these two cytochromes. The kinetics of induction were defined by measuring these parameters after a single phenobarbital injection. Cytochrome P-450 mRNA levels reached maximum induction at 16 hr, returning to basal values by 48 hr. In contrast, total cytochrome P-450 microsomal protein content reached maximum induction after 33 hr. Hepatocytes of the distal half of the hepatic acinus responded to phenobarbital with higher levels of cytochromes P-450b and P-450e mRNAs than proximal hepatocytes. These results indicated that there is modulation of the expression of the cytochromes P-450b and P-450e genes within the hepatic acinus.