Del Vecchio P J, Smith J R
J Cell Physiol. 1981 Sep;108(3):337-45. doi: 10.1002/jcp.1041080307.
Angiotensin-converting enzyme (EC 3.4.51.1) is a carboxyterminal dipeptidyl peptidase. The enzyme catalyzes the conversion of the decapeptide angiotensin I to the octapeptide angiotensin II. In addition, the enzyme catabolizes bradykinin. Because of these actions, the enzyme is of pivotal importance in blood pressure homeostasis. Numerous investigators have demonstrated the presence of the enzyme in association with endothelial cells but relatively little is known concerning the factors controlling the expression enzyme activity by endothelial cells in culture. We have demonstrated that endothelial cells in culture do not express significant amounts of enzyme activity until several days after growth ceases due to high cell density. This is important because it demonstrates a change in function with stage of growth in culture and a possible difference in functional capabilities between nondividing endothelial cells and cells that are dividing in response to injury. Since density-dependent expression of differentiated traits does not appear to be unique to endothelial cells an understanding of the mechanisms underlying this phenomenon may provide a general explanation for the expression of differentiated traits by cultured cells.
血管紧张素转换酶（EC 3.4.51.1）是一种羧基末端二肽基肽酶。该酶催化十肽血管紧张素I转化为八肽血管紧张素II。此外，该酶还分解缓激肽。由于这些作用，该酶在血压稳态中至关重要。众多研究者已证明该酶与内皮细胞相关，但关于培养的内皮细胞控制该酶活性表达的因素却知之甚少。我们已证明，培养的内皮细胞在因高细胞密度而停止生长数天后才会表达大量的酶活性。这一点很重要，因为它表明了培养过程中随着生长阶段功能发生的变化，以及非分裂内皮细胞与因损伤而分裂的细胞在功能能力上可能存在的差异。由于依赖密度表达分化特性似乎并非内皮细胞所特有，了解这一现象背后的机制可能为培养细胞分化特性的表达提供一个普遍的解释。
