salbutamol and procaterol ( selective beta 2 agonists ) also produced dose-dependent negative chronotropic effects , which were dose-dependently inhibited by pretreatment with 10 ( -8 ) -10 ( -7 ) m propranolol , but not by 10 ( -7 ) m metoprolol .
C1372752
negative chronotropic
C0025859
metoprolol