Jungermann K
Institut für Biochemie, Georg-August-Universität, Göttingen, Federal Republic of Germany.
Semin Liver Dis. 1988 Nov;8(4):329-41. doi: 10.1055/s-2008-1040554.
Periportal and perivenous hepatocytes differ in their content of enzymes and subcellular structures and thus in their metabolic capacities. Therefore, the model of metabolic zonation proposes that: (1) periportal hepatocytes catalyze predominantly oxidative energy metabolism with beta-oxidation and amino acid catabolism as well as ureagenesis for glycogen synthesis and glucose release, bile formation with cholesterol synthesis and protective metabolism; and (2) perivenous hepatocytes mediate preferentially glucose uptake for glycogen synthesis, glycolysis, and liponeogenesis as well as ketogenesis, glutamine formation, and xenobiotic metabolism. Periportal and perivenous hepatocytes are under the control of a different input of humoral and nervous signals, because concentration gradients of oxygen, substrates, and hormones are established during passage of blood through the liver and because gradients of nerve densities seem to exist. In periportal and perivenous hepatocytes gene expression can be different due to the zonal gradients in oxygen and hormone concentrations as well as nerve densities. The functional specialization of periportal and perivenous hepatocytes has been demonstrated especially well for carbohydrate, amino acid and ammonia, and xenobiotic metabolism as well as for bile formation by different techniques: Calculation of metabolic rates based on the zonal distributions of enzymes and metabolites, measurements of rates in periportal-like and perivenous-like hepatocytes in cell culture and in hepatocyte populations enriched in periportal and perivenous cells as well as in perfused livers during orthograde and retrograde flow using standard methods and noninvasive techniques with surface microlight guides and miniature oxygen electrodes.
门周肝细胞和中央静脉周围肝细胞在酶含量、亚细胞结构以及代谢能力方面存在差异。因此，代谢分区模型提出：（1）门周肝细胞主要催化氧化能量代谢，包括β氧化、氨基酸分解代谢以及尿素生成，以进行糖原合成和葡萄糖释放、胆汁形成以及胆固醇合成和保护性代谢；（2）中央静脉周围肝细胞优先介导葡萄糖摄取以进行糖原合成、糖酵解、脂肪生成以及酮体生成、谷氨酰胺形成和外源性物质代谢。门周肝细胞和中央静脉周围肝细胞受到不同的体液和神经信号输入的控制，这是因为血液流经肝脏时会形成氧气、底物和激素的浓度梯度，而且似乎存在神经密度梯度。由于氧气和激素浓度以及神经密度的区域梯度，门周肝细胞和中央静脉周围肝细胞中的基因表达可能会有所不同。门周肝细胞和中央静脉周围肝细胞的功能特化在碳水化合物、氨基酸和氨、外源性物质代谢以及胆汁形成方面通过不同技术得到了很好的证明：基于酶和代谢物的区域分布计算代谢率，在细胞培养中以及在富含门周和中央静脉周围细胞的肝细胞群体中，以及在使用标准方法和具有表面微光导和微型氧电极的非侵入性技术进行顺行和逆行灌注的肝脏中，测量门周样和中央静脉周围样肝细胞中的代谢率。
