METH exposure impairs GLUT1 expression in microvessels and brain tissues. (A) Expression of GLUT1 (green) in microvessel capillaries of brain tissue section in control (a), 200 μM METH (b) and 200 μM METH+200 μM ALC (c). The expression of GLUT1 (green) merged with vWF (red) in enlarged view of a single capillary is shown in control (d-f), 200 μM METH (g-i) and 200 μM METH+200 μM ALC (j-l). (B) Expression of 55 kDa isoform GLUT1 protein in brain microvessels and (C) levels of 45 kDa isoform GLUT1 protein in brain tissue protein extract. Bar graphs show the results, which are expressed as ratio of GLUT1 to that of α-actin bands and presented as the mean values (± SEM; n = 3). **Statistically significant (p < 0.01) compared with controls. Scale bar indicated 20 μm in panels of a-c and 5 μm (shown in d) in panels of d-l.