PATHWAY ACROSS BLOOD-BRAIN-BARRIER OPENED BY THE BRADYKININ AGONIST, RMP-7

Citation
E. Sanovich et al., PATHWAY ACROSS BLOOD-BRAIN-BARRIER OPENED BY THE BRADYKININ AGONIST, RMP-7, Brain research, 705(1-2), 1995, pp. 125-135
Citations number
52
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences
Journal title
ISSN journal
0006-8993
Volume
705
Issue
1-2
Year of publication
1995
Pages
125 - 135
Database
ISI
SICI code
0006-8993(1995)705:1-2<125:PABOBT>2.0.ZU;2-0
Abstract
The route taken by lanthanum (MW 139) across cerebral endothelium was delineated when the blood-brain barrier was opened by RMP-7, a novel b radykinin agonist. Balb C mice were infused through a jugular vein wit h LaCl3 with or without RMP-7 (5 mu g/kg). Ten minutes later, the brai ns were fixed with aldehydes and processed for electron microscopy. Th e patency of the junctions between endothelial cells was estimated by counting the number of junctions penetrated by LaCl3. Tracer penetrate d the junctions in about 25% of microvessels in vehicle infused, contr ol mice and about 58% in the RMP-7 group, where more junctions per ves sel were also penetrated. The LaCl3 then penetrated the basal lamina i n about 20% of all microvessels in the RMP-7 group, versus 0.50% in th e control group. From the basal lamina, the tracer entered perivascula r spaces in about 13% of all microvessels in the RMP-7 group and about 0.07% in the controls. Very few endocytic pits or vesicles in the RMP -7 group were labeled, so LaCl3 did not cross endothelium by transcyto sis. The increased number of tight junctions penetrated by tracer and its spread into periendothelial basal lamina and interstitial clefts i ndicated, therefore, a paracellular route of exudation in the RMP-7 tr eated animals.