Rate-limiting Steps in the [3-Adrenergic Stimulation of Cardiac Calcium Current

I N T R O D U C T I O N Binding of f3-adrenergic agonists to their receptors on cardiac myocytes triggers a cascade o f events that includes activation o f the G protein Gs, stimulation o f adenylyl cyclase (AC) activity and synthesis of cAMP, activation o f cAMP-dependent protein Address reprint requests to Dr. H. Criss HartzeU, The HeartCell Laboratory, Department of Anatomy and Cell Biology, Emory University School of Medicine, Atlanta, GA 30033. j. GEN. PHYSIOL. ~])The Rockefeller University Press" 0022-1295/93/03/0337/17 $2.00 337 Volume 101 March 1993 337-353 on S etem er 9, 2011 jgp.rress.org D ow nladed fom Published March 1, 1993