Figure 2.

AR-mediated control of tension in VSMC. Inhibition of K_V induces depolarization which will activate Ca²⁺ influx through Ca_v and thus precipitates vasoconstriction due to a rise in [Ca²⁺]_i. K_V is stimulated by cAMP-PKA signaling, and in pathophysiologic conditions such as that in SHR may be inhibited by PLC. The BRL37344-induced β₃AR-G_i signaling and increased TPR was only observed in WKY during tyramine-induced norepinephrine release. Ca_v, voltage sensitive Ca²⁺ channels; K_V, voltage sensitive K⁺ channels; 4AP, the K_V inhibitor 4-aminopyridine; PKA, protein kinase A; Arrow, positive action; Blunted arrow, negative action.