Ody C, Junod A F
Am J Physiol. 1977 Mar;232(3):C95-8. doi: 10.1152/ajpcell.1977.232.3.C95.
Converting enzyme activity was studied in endothelial cells, isolated from pig pulmonary arteries and aorta by exposure to collagenase. The measure was based on the release of His-Leu from Z-Phe-His-Leu was related to the DNA content of the cellular suspension. The same activity was found in the two types of endothelium: 1 nmol His-Leu/mug DNA per 30 min. Subendothelial cells showed a very low activity, amounting to 10% of the value found for the endothelium. The enzyme activity was 2inhibited by the nonapeptide SQ 20881, EDTA, and the lack of Cl- in the same fashion for the two types of endothelium. The presence of another enzyme hydrolyzing His-Leu was detected in both endothelial populations. Isolated fragments of plasma membrane, however, exhibited only converting enzyme activity. It can be concluded that endothelial cells isolated from large vessels of the pulmonary and the systemic circulations have similar properties when dipeptidyl carboxypeptidase activity is measured.
通过胶原酶处理从猪肺动脉和主动脉分离出内皮细胞，研究了其转化酶活性。该测量基于从Z-苯丙氨酸-组氨酸-亮氨酸释放组氨酸-亮氨酸，其与细胞悬液的DNA含量相关。在两种类型的内皮中发现了相同的活性：每30分钟每微克DNA释放1纳摩尔组氨酸-亮氨酸。内皮下细胞活性非常低，仅为内皮细胞活性值的10%。两种类型的内皮中，九肽SQ 20881、乙二胺四乙酸（EDTA）以及缺乏氯离子均以相同方式抑制该酶活性。在两种内皮细胞群体中均检测到另一种水解组氨酸-亮氨酸的酶。然而，分离的质膜片段仅表现出转化酶活性。可以得出结论，当测量二肽基羧肽酶活性时，从肺循环和体循环的大血管分离出的内皮细胞具有相似的特性。
