Skip to main content
. 2020 Dec 3;9(12):2594. doi: 10.3390/cells9122594

Figure 1.

Figure 1

The three adrenoceptor (AR) subfamilies and their subtypes. α1-, α2-, and β-ARs mainly couple to Gq/11, Gi, and Gs proteins, respectively. To be more exact, the α2A-AR subtype has an unusual dual pharmacological effect by coupling to Gi proteins when concentrations of agonists are low and mainly coupling to Gs proteins when concentrations are high [43]. β-ARs are mainly coupled to Gs proteins and both β1- and β2-AR are able to switch their G protein-coupling specificity from Gs to Gi proteins [44].