Restricted transport of anti‐transferrin receptor antibody (OX26) through the blood–brain barrier in the rat

摘要: Anti-transferrin receptor IgG2a (OX26) transport into the brain was studied in rats. Uptake of OX26 capillary endothelial cells (BCECs) > 10-fold higher than isotypic, non-immune (Ni-IgG2a) when expressed as % ID/g. Accumulation 15 postnatal (P)-day-old rats P0 and adult (P70) Iron-deficiency did not increase uptake P15 Three attempts were made to investigate from BCECs further brain. (i) Using a depletion technique, 6-9% identified post-capillary compartment consisting parenchyma minus BCECs. (ii) In cisternal CSF, volume distribution for Ni-IgG2a corrected plasma concentration. (iii) Immunohistochemical mapping revealed presence almost exclusively BCECs; extravascular staining observed only neurons situated periventricularly. The data support hypothesis facilitated due transferrin receptors at blood-brain barrier (BBB). However, accumulation too small justify conclusion receptor-mediated transcytosis occurring component may result diphasic that involves high-affinity by BCECs, clearly exceeding Ni-IgG2a, followed second mechanism releases non-specifically periventricular localization suggests probably also derives across blood-CSF barrier.