Figure 2.

Expression and localization of Oatp1c1 in rat brain/retinal capillary endothelial cells and RPE. (a) Immunoblotting with Oatp1c1 antibodies using proteins (20 μg/lane) prepared from rat brain capillary fraction (a₁), brain (a₁ and a₂), retina (a₃), and kidney (a₂, negative control) in the absence [antigen(-)] or presence [antigen(+)] of Oatp1c1 antigens. Arrow heads indicate the expected position of the band. (b) Oatp1c1 immunofluorescence in the rat cerebral cortex (Cx). (c) Oatp1c1 (green, c₁ and c₃) overlapped with GLUT1 (red, c₂ and c₃) in brain capillaries. (d) Oatp1c1 (green) in the retinal capillaries (arrow heads and double arrow heads) and the RPE (arrows and triple arrow heads) of rat retina. Oatp1c1 was observed around the nucleus (blue) of retinal capillaries (arrow head and double arrow head, d₂) and around the nucleus of the RPE (arrows and triple arrow heads, d₃). (e) Oatp1c1 (green, e₁ and e₂) overlapped with GLUT1 (red, e₁ and e₃) on the abluminal (an arrow head) and luminal membrane (a double arrow head) of retinal capillaries. The blue line between A and B indicates the scanned line (e₁), and the relative fluorescence intensity is plotted in green for Oatp1c1 and red for GLUT1 (e₄), which is expressed in the abluminal (AL) and luminal (L) membrane of the retinal capillaries. (f) Oatp1c1 (green, f₁ and f₂) overlapped with GLUT1 (red, f₁ and f₃) on the apical (arrows) and basolateral membrane (triple arrow heads) of rat RPE. The blue line between A and B indicates the scanned line (f₁), and the relative fluorescence intensity is plotted in green for Oatp1c1 and red for GLUT1 (f₄), which is expressed in the apical (Ap) and basolateral (Ba) membrane of the RPE. Scale bar: 50 μm (b, d₁), 5 μm (c, d₂, e), 10 μm (d₃, f).