14th International Congress
THE "NEW FRONTIERS"
OF ARRHYTHMIAS 2000

Jan. 29 - Feb. 5, 2000
Marilleva, Trento, Italy

RT-30

Roles of b1 and b2 adrenergic receptors in L-type calcium current

Zsolt Nagykaldi, David Kem, Ralph Lazzara, Bela Szabo.
University of Oklahoma, USA

Introduction

b₁ and b₂ adrenergic receptors (b₁ AR, b₂ AR) are present in the mammalian myocardium. They differ in distribution, b₁ AR dominating in ventricular myocardium, while b₂ AR are relatively more prominent in the specialized tissues^1-3. The relatives roles and interaction of b₁ AR and b₂ AR, with respect to the various effectors and transduction systems for adrenergic actions, has not been fully clarified. It is well established that stimulation of b₁ AR enhances L-type calcium current (I_CaL)^4,5 but studies of the effects of b₂ AR stimulation have been inconsistent⁵. The purpose of these studies was to determine the effects of b₂ AR stimulation on ICaL and the interaction of b1 AR and b₂ AR on I_CaL.

Key Words