Heterogeneous distribution of angiotensin I-converting enzyme (CD143) in the human and rat vascular systems: Vessel, organ and species specificity

► High ACE immunoreactivity in endothelial cells of human small muscular arteries and arterioles. ► Endothelial cells of human large arteries and veins were poorly reactive or negative for ACE. ► 20% of capillary endothelial cells in each human organ stained for ACE, except lung and kidney. ► In the human lung all capillary endothelial cells were labeled intensively for ACE. ► In the human kidney the entire vasculature was devoid of ACE.