PMC:2678986 / 7274-8041 JSONTXT

{"target":"https://pubannotation.org/docs/sourcedb/PMC/sourceid/2678986","sourcedb":"PMC","sourceid":"2678986","source_url":"https://www.ncbi.nlm.nih.gov/pmc/2678986","text":"Substances can cross non-barrier capillary walls by a variety of routes, either between the cells of the endothelium (paracellular movement), directly through the cell wall (active transport, facilitated and/or passive diffusion) or through vesicular transport (endocytosis). However, the cerebral capillaries are the site of the blood–brain barrier (BBB) and consequently these three routes are restricted by the presence of tight junctions between the endothelial cells, the lack of intracellular fenestrations in brain endothelial cells, the paucity of endocytotic vesicles as well as by the presence of multiple metabolic enzymes and diverse transport systems (Fig. 1). Thus the entry of anti-HIV drugs/substances by unregulated pathways or by leakage is limited.","tracks":[]}