Olson K R, Lipke D, Datta Munshi J S, Moitra A, Ghosh T K, Kunwar G, Ahmad M, Roy P K, Singh O N, Nasar S S
Indiana University School of Medicine, University of Notre Dame 46556.
Gen Comp Endocrinol. 1987 Dec;68(3):486-91. doi: 10.1016/0016-6480(87)90088-8.
Angiotensin-converting enzyme (ACE) was measured in tissue homogenates from the African lungfish and six species of air-breathing teleosts (Heteropneustes fossilis, Clarias batrachus, Channa gachua, Anabas testudineus, Notopterus chitala, and Monopterus cuchia) using a standard spectrophotometric assay. In most species, the highest levels of ACE activity were found in the respiratory organs (gills and/or accessory respiratory organs). ACE was also found in heart and kidney tissues from most species and occasionally in liver. Converting enzyme was not found in skin or skeletal muscle from any species and only in blood from H. fossilis and brain from C. batrachus. Captopril, a potent inhibitor of mammalian ACE, inhibited enzymatic activity from all tissues except C. gachua heart and liver and A. testudineus heart. As fish make the transition from aquatic to aerial respiration the gill microcirculation is usually reduced in size and the accessory respiratory organs become elaborated and occupy a more central position in the vascular tree. The presence of ACE in accessory respiratory organs of air-breathing fish appears to greatly enhance the metabolic efficiency of this enzyme on circulating substrates.
采用标准分光光度法测定了非洲肺鱼和六种呼吸空气的硬骨鱼（印度胡鲶、胡子鲶、月鳢、攀鲈、长背鱼和黄鳝）组织匀浆中的血管紧张素转换酶（ACE）。在大多数物种中，ACE活性最高的部位是呼吸器官（鳃和/或辅助呼吸器官）。在大多数物种的心脏和肾脏组织中也发现了ACE，偶尔在肝脏中也有发现。在任何物种的皮肤或骨骼肌中均未发现转换酶，仅在印度胡鲶的血液和胡子鲶的大脑中发现。卡托普利是一种有效的哺乳动物ACE抑制剂，它能抑制除月鳢心脏和肝脏以及攀鲈心脏之外所有组织的酶活性。随着鱼类从水生呼吸转变为空气呼吸，鳃微循环通常会变小，而辅助呼吸器官会变得更加发达，并在血管系统中占据更中心的位置。在呼吸空气的鱼类的辅助呼吸器官中存在ACE，这似乎极大地提高了该酶对循环底物的代谢效率。
