Fig. 6
Effect of dopamine receptor D4 (DRD4) on Ang II-induced proliferation of primary vascular smooth muscle cells (VSMCs) in broilers. a, b Effect of DRD4 agonist (D4A, HY-101384A) or DRD4 inhibitor (D4I, HY-B0965) on the proliferation of broiler primary VSMCs. c, d Effect of D4A or D4I on Ang II-mediated proliferation of broiler primary VSMCs. (n = 9, **P < 0.01 *P < 0.05 vs. control). e Specificity of DRD4 on the proliferation of broiler primary VSMCs. VSMCs were treated in four ways: control group (normal culture for 24 h), Ang II group (incubated with 10− 4 mM of Ang II for 24 h), Ang II + D4A (incubated with 10− 5 mM of D4A for 2 h before and then with 10− 4 mM of Ang II for 24 h), Ang II + D4A + D4I (incubated with 10− 5 mM of D4I for 2 h and then with 10− 5 mM of D4A for 2 h, and finally with 10− 4 mM of Ang II for 24 h) (n = 9, **P < 0.01 vs. control, ## P < 0.01 vs. Ang II + D4A)