Paul M, Stoll M, Kreutz R, Fernandez-Alfonso M S
University Hospital Benjamin Franklin, Institute for Clinical Pharmacology, Berlin, Germany.
Basic Res Cardiol. 1996;91 Suppl 2:57-63. doi: 10.1007/BF00795364.
Angiotensin converting enzyme (ACE) is a key factor in the regulation of two peptide systems: the renin angiotensin system (RAS) and the kinin-kallikrein system (KKS). Since it is involved in the biosynthesis of Angiotensin II (Ang II) as well as in the degradation of bradykinin (BK) it could play an important role in cardiovascular physiology and pathophysiology. ACE is widely expressed in the heart and upregulated in pathophysiological situations such as heart failure and cardiac hypertrophy. In addition, inhibition of ACE has beneficial effects in these conditions. Whereas the regulation of cardiac ACE has been studied extensively, little is known concerning the cellular expression of ACE in cardiac tissue. To define the cellular localization of ACE mRNA expression in the rat heart, we separated coronary microvascular endothelial cells from cardiac myocytes using differential centrifugation and growth on selective media. ACE mRNA expression was measured by a specific polymerase chain reaction assay after reverse transcription (RT-PCR) in different cardiac cells. The studies showed that ACE is differentially expressed in endothelial cells as well as in cardiac myocytes. This differential regulation of ACE in myocytes and non-myocytes may play a role for the diverse actions of the cardiac angiotensin system under physiological and pathological conditions.
血管紧张素转换酶（ACE）是调节两个肽系统的关键因素：肾素血管紧张素系统（RAS）和激肽-激肽释放酶系统（KKS）。由于它参与血管紧张素II（Ang II）的生物合成以及缓激肽（BK）的降解，它可能在心血管生理和病理生理中发挥重要作用。ACE在心脏中广泛表达，并在诸如心力衰竭和心肌肥大等病理生理情况下上调。此外，抑制ACE在这些情况下具有有益作用。虽然已经广泛研究了心脏ACE的调节，但关于ACE在心脏组织中的细胞表达知之甚少。为了确定大鼠心脏中ACE mRNA表达的细胞定位，我们使用差速离心法从心肌细胞中分离出冠状动脉微血管内皮细胞，并在选择性培养基上培养。在不同的心脏细胞中，通过逆转录（RT-PCR）后的特异性聚合酶链反应测定法测量ACE mRNA表达。研究表明，ACE在内皮细胞和心肌细胞中差异表达。ACE在心肌细胞和非心肌细胞中的这种差异调节可能在生理和病理条件下心脏血管紧张素系统的不同作用中发挥作用。
