Open AccessPericytes of the brain microvasculature express γ‐glutamyl transpeptidase
Author(s) -
FREY Andreas,
MECKELEIN Barbara,
WEILERGÜTTLER Hartmut,
MÖCKEL Babette,
FLACH Regina,
GASSEN Hans G.
Publication year - 1991
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1991.tb16391.x
Subject(s) - pericyte , microvessel , immunohistochemistry , endothelium , biology , antibody , population , endothelial stem cell , pathology , immunofluorescence , blood–brain barrier , microbiology and biotechnology , parenchyma , chemistry , biochemistry , immunology , medicine , in vitro , endocrinology , central nervous system , environmental health
The expression of γ‐glutamyl transpeptidase (GGT) is a specific property of the brain capillary endothelium that constitutes the blood‐brain barrier. We report here the detection of GGT, not only in endothelial cells, but also in pericytes, demonstrating that a brain capillary‐specific pericyte population exists. We raised antibodies to GGT using a porcine brain microvessel GGT–protein‐A (staphylococcal protein A) fusion protein as antigen which was expressed in Escherichia coli . The immunohistochemical analysis of the subcapillary distribution of GGT in procine brain cortex and cerebellum sections by both light and electron microscopy revealed the expression of GGT in the capillary‐adjacent pericytes in addition to the GGT‐positive endothelial layer. We confirmed these data for cultured porcine brain microvascular endothelial cells and pericytes. GGT immunofluorescence could be detected in both cell types in culture. Endothelial cells exhibited a weak staining, whereas pericytes were strongly positive for GGT. Due to the high phagocytotic activity of pericytes and their location on the abluminal surface of the microvessels, we propose a possible protective or detoxifying function of GGT in cerebrovascular pericytes.