Brain parenchyma vessels and the angiotensin system.
It is now recognized that the brain contains an autonomous angiotensin (AG) system, including the aminopeptidases A and N required for angiotensin metabolism. Using immunohistochemical techniques, we show that capillary pericytes and periendothelial cells of other vessels express aminopeptidase A (APA) and aminopeptidase N (APN) at their plasma membrane in adult mouse brain parenchyma. We therefore investigated the localization of angiotensin II(III), known as putative substrates for these enzymes, as well as that of their precursor angiotensin I. We report here the presence of immunoreactivity to angiotensin I and II(III) around most brain vessels. Angiotensins are present at the plasma membrane of brain parenchymal cells, presumably perivascular astrocytes which are also immunoreactive to AT1-receptor antibodies. The very close relationship between AGII(III) and their metabolizing enzymes APA and APN suggests a specific functional role for brain perivascular angiotensins.
Alliot
F
F
CNRS UPR 9035 and ER 1783 'Développement et Immunité du Système Nerveux Central', 15 rue de l'Ecole de Médecine, 75270, Paris cedex 06, France.
Rutin
J
J
Leenen
P J
PJ
Pessac
B
B
D000626:Aminopeptidases / Q000378:metabolism; D000804:Angiotensin II / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001921:Brain / Q000098:blood supply*; D018826:CD13 Antigens / Q000378:metabolism; D043384:Glutamyl Aminopeptidase; D007150:Immunohistochemistry; D008666:Metalloendopeptidases / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000378:metabolism
D000804:Angiotensin II; D000626:Aminopeptidases; D018826:CD13 Antigens; D043384:Glutamyl Aminopeptidase; D008666:Metalloendopeptidases