Autoradiographic Studies of Beta-Adrenergic Receptors

Longitudinal distribution of Na+ and Ca2+ channels and β‐adrenoceptors on the sarcolemmal membrane of frog cardiomyocytes

“…A number of methods have been developed over the last twenty years to investigate the spatial distribution of ion channels and membrane receptors on the sarcolemmal membranes of various cell types. For instance, auto‐radiography studies using selective radiolabelled ligands have enabled determination of the distribution of muscarinic (Hartzell, 1980) and β‐adrenergic receptors (Molenaar, Canale & Summers, 1987; Wolfe, 1991) in cardiac myocytes. Immunocytochemical methods using either monoclonal antibodies (Westenbroek, Ahlijanian & Catterall, 1990; Carl et al 1995; Carrington, Lynch, Moore, Isenberg, Fogarty & Fay, 1995; Robitaille, Bourque & Vandaele, 1996) or biologically active fluorescent and biotinylated derivatives of a selective ligand (Jones, Kunze & Angelides, 1989) have been used to examine the localization of voltage‐dependent Ca 2+ channels at the neuromuscular junction (Robitaille et al 1996), in neurones (Jones et al 1989; Westenbroek et al 1990) and in smooth (Carrington et al 1995) and cardiac muscle cells (Carl et al 1995).…”

“…In the heart, a number of studies using autoradiographic and immunocytochemical methods have examined the distribution of receptors and channels throughout the heart structure (see e.g. Hartzell, 1980; Molenaar et al 1987; Wolfe, 1991; Carl et al 1995; Gao, Puri, Gerhardstein & Hosey, 1997). However, most of these studies do not provide any information on the functional state of the proteins investigated.…”