Spontaneous activation of β2- but not β1-adrenoceptors expressed in cardiac myocytes from β1β2 double knockout mice - Ying-Ying Zhou; Dongmei Yang; Wei-Zhong Zhu; Sheng-Jun Zhang; Ding-Ji Wang; Dan K. Rohrer; Eric Devic; Brian K. Kobilka; Edward G. Lakatta; Heping Cheng; Rui-Ping Xiao (Molecular Pharmacology, 2000)