Moorman A F, Vermeulen J L, Charles R, Lamers W H
Department of Anatomy and Embryology, University of Amsterdam, The Netherlands.
Hepatology. 1989 Mar;9(3):367-72. doi: 10.1002/hep.1840090305.
Immunohistochemical analysis of human liver (8 to 94 years) shows a compartmentation of ammonia-metabolizing enzymes across the acinus. The highest concentration of carbamoylphosphate synthetase (ammonia) is found in the parenchymal cells around the terminal portal venules. Glutamine synthetase is found in a small pericentral compartment two to three cells thick. In contrast to observations in rat liver, in human liver a well-recognizable intermediate zone can be distinguished in which neither enzyme can be detected. This intermediate zone is not yet established at the age of 8 years but can be recognized in livers from 25 years onward. Carbamoylphosphate synthetase can already be detected in the liver of human fetuses at 5 weeks of development. The enzyme distribution reveals a random heterogeneity among the hepatocytes, suggesting that not all hepatocytes start to accumulate carbamoylphosphate synthetase at the same time. From 9 weeks of development onward, the enzyme becomes homogeneously distributed throughout the liver parenchyma until at least 2 days after birth. Glutamine synthetase cannot be detected during this period. In addition, the definitive architecture of the acinus is not yet completed at birth. These results therefore support the idea that in human liver, metabolic zonation with respect to NH3 metabolism exists as it does in rat liver. Furthermore, the data show that this functional compartmentation becomes established concomitant with the development of the acinar architecture.(ABSTRACT TRUNCATED AT 250 WORDS)
对人肝脏（8至94岁）进行的免疫组织化学分析显示，氨代谢酶在腺泡内呈区室化分布。氨甲酰磷酸合成酶（氨）的最高浓度出现在终末门静脉周围的实质细胞中。谷氨酰胺合成酶存在于一个位于中央静脉周围、厚度为两到三个细胞的小区域内。与大鼠肝脏中的观察结果不同，在人肝脏中可以区分出一个明显的中间区域，在该区域两种酶均无法检测到。这个中间区域在8岁时尚未形成，但在25岁及以上的肝脏中可以识别。氨甲酰磷酸合成酶在人类胎儿发育5周时的肝脏中就已可检测到。酶的分布显示肝细胞之间存在随机异质性，这表明并非所有肝细胞都同时开始积累氨甲酰磷酸合成酶。从发育9周起，该酶在整个肝实质中均匀分布，至少持续到出生后2天。在此期间无法检测到谷氨酰胺合成酶。此外，腺泡的最终结构在出生时尚未完成。因此，这些结果支持了这样一种观点，即人肝脏中存在与大鼠肝脏类似的关于NH3代谢的代谢分区。此外，数据表明这种功能区室化是随着腺泡结构的发育而建立的。（摘要截选至250字）
