Figure 10. Selective inhibition of α₁ARs or α₂ARs improves ROV in upstream branch orders of GM in old mice .

Peak ROV (% max) in FA, 1A, 2A and 3A following 100, 250, 500 and 1000 ms contraction in the GM of old mice. Across contraction durations, selective inhibition of α₁ARs (PZ, 10⁻⁸  m) or of α₂ARs (RW, 10⁻⁷  m) improved ROV in FA while inhibition of α₂ARs improved ROV in 1A. Nevertheless, inhibition of either αAR subtype alone had no effect in 2A or 3A. ^Δ P < 0.05 main effect of branch order; ^# P < 0.05, main effect of treatment; ^Φ P < 0.05, PZ vs. control, ^ψ P < 0.05, RW vs. control. Summary data are means ± SEM for n = 6 old mice.