The expression of GLUT1 in the endothelial cell membranes has been measured in several different ways: by cytochalasin-B binding, by specific antibody binding, and by proteomic methods (see Table 2 for references). In the proteomic studies from the group of Terasaki, Uchida, Ohtsuki and colleagues, GLUT1 was found to be the most highly expressed of all the transporters that are present in the membranes of the endothelial cells [306].
Table 2 Expression of GLUT1 at the blood–brain barrier
Source Methoda Species Expression/pmol mg−1
Luminal Totalb Abluminal
Relative to microvessel protein
Dick et al. [303] Cytochalasin B binding Rat, pig 69–80
Kalaria et al. [571] Cytochalasin B binding Human 42
Farrell and Pardridge [572] Immunogold e.m Rat 12%c 100%c 48%c
Cornford et al. [573] Immunogold e.m Human 48% 100% 18%
Vannucci et al. [574] Cytochalasin B binding Rat 40–125
Kamiie et al. [182] Proteomics Mouse 90
Uchida et al. [184] Proteomics Human 139
Shawahna et al. [176] Proteomics Human 78.5
Hoshi et al. [185] Lysate digestion proteomics Rat 84–98
Relative to membrane protein
Simpson et al. [575] Fractionation, cytochalasin B binding Bovine 620 280
Kubo et al. [58] Fractionation, proteomics Porcine 79% 21%
Zhang et al. [188] Proteomics Porcine 300
aFractionation = fractionation of isolated plasma membranes
bFor immunogold detection, values are percentages of the immunogold particles where the total includes cytoplasmic
cAntigen for the antibody used by Farrell and Pardridge appears to be partially masked for GLUT1 most markedly in the luminal membrane in bovine endothelial cells [575]