Receptor localisation and effect of alpha receptors

Apart from differences in potency and affinity, the effect of endogenous ligands or drugs also depend on the localisation of certain receptor types in different tissues and organs.

The graphics show the differences in localisation of the α-adrenergic and β-adrenergic receptors. Sometimes both receptors are localised in the same tissue or organ, but then they exert different effects or the same effects but in different strength.