Histamine H2 receptor
（重定向自H2 receptor）
![](/Images/godic/202501/16/PBB_GE_HRH2_220805_at_tn5027.png")
H2 receptors are positively coupled to adenylate cyclase via Gs. It is a potent stimulant of cAMP production, which leads to activation of protein kinase A. PKA functions to phosphorylate certain proteins, affecting their activity. The drug betazole is an example of a histamine H2 receptor agonist.