α-Adrenoceptor assays.

α-Adrenoceptors mediate responses to activation of both peripheral sympathetic nerves and central noradrenergic neurons. They also serve as autoreceptors that modulate the release of norepinephrine (NE) and other neurotransmitters. There are two major classes of α-adrenoceptors, the α(1)- and α(2). Each class is subdivided into three subtypes: α(1A), α(1B), α(1D), and α(2A), α(2B), α(2C). Described in this unit are in vitro isolated tissue methods used to study α-adrenoceptor functions and to identify novel ligands for these receptors. Detailed protocols describing use of isolated tissues to study the various α(1)- and α(2)-adrenoceptor subtypes are provided.