RECEPTOR-MEDIATED ANGIOTENSIN-II TRANSCYTOSIS BY BRAIN MICROVESSEL ENDOTHELIAL-CELLS

Angiotensin II (Ang II) uptake and transport across monolayers of bovi ne brain microvessel endothelial cells (BMECs) was demonstrated. Ang I I transport was linear up to 2 h, saturable with a K-m of 1.7 nM, and tended to be polarized with the apical-to-basolateral transport being greater. [H-3]Ang II transport was found to be inhibited by excess unl abeled Ang II, by the Ang II analog sarathrin, and by the endocytic in hibitor phenylarsine oxide. Ang II-(2-8) and-(3-8) were shown to signi ficantly increase the transport of Ang II. These results demonstrate f or the first time the receptor-mediated transcytosis of Ang II across brain microvessel endothelium. (C) 1998 Elsevier Science Inc.