Figure 5
Dilatory capacity of pial arterioles of Tat-transgenic mice is decreased. (A-F) Representative images of dilatory response of pial arterioles in wild type (WT), Tat-transgenic (Tat-tg), and Tat-tg mice treated with PDE5 inhibitor gisadenafil (PDEi), taken before (A, C, E) and after (B, D, F) exposure to 30 seconds of 6% CO2. 25X magnification. Arrows point to representative arterioles. Scale bar is 50 micrometers (μm). (G) Average magnitude of vessel dilation after exposure to CO2 (all vessels; initial diameters 1 to 50 μm). Data shown were collected from seven WT mice (a total of 23 arterioles were analyzed), seven Tat-tg mice (a total of 36 arterioles), and seven Tat-tg mice treated with PDEi (a total of 45 arterioles). (H) Average magnitude of vessel dilation after exposure to CO2 (small vessels only; initial diameters 1 to 25 μm). These data are a subset of those shown in (G). (I). Average magnitude of vessel dilation after exposure to CO2 (larger vessels only; initial diameters 26 to 50 μm). These data are a subset of the data shown in (G). G-I. Data are plotted as box- plots. Maximum and minimum outliers are represented by whisker endpoints. Box segmentation represents lowest datum within 1.5 interquartile range of lower quartile, median and highest datum within 1.5 interquartile range of the upper quartile. Statistical significance denoted as *P <0.05; **P <0.01; ***P <0.001; or n.s., no significant difference; t-test