Fig. 7.
Effects of α1-adrenergic blockade [prazosin (Pra)] on femoral artery cytosolic Ca2+ concentration ([Ca2+]CYT), diameter, and tone in femoral arteries of control (Ctrl) and smooth muscle-specific Na+/Ca2+ exchanger-1 (NCX1) overexpression [transgenic (TG)] mice. A: diameters of exposed femoral arteries of Ctrl and TG mice in vivo as well as the effects of superfusion with 300 nM Pra. Passive diameter (PD) (arteries superfused with Ca2+-free medium) is also shown. Ctrl PD = 403 ± 13 μm (n = 6); TG PD = 397 ± 12 μm (n = 6). B and C: [Ca2+]CYT and arterial tone (as %PD), respectively, in Ctrl and TG mouse arteries under basal conditions and during superfusion with 300 nM Pra. Pra reduced [Ca2+]CYT and tone to a greater extent in TG mice than in Ctrl mice. [Ca2+]i, intracellular Ca2+ concentration. Values are means ± SE. Statistics were by two-way ANOVA. *P < 0.05, **P < 0.01, and ***P < 0.001 vs. basal Ctrl mice; ##P < 0.01 and ###P < 0.001 vs. basal TG mice. Numbers of mice are in parentheses.