mabuterol , injected into the sinus node artery of the isolated atrium , dose-dependently increased atrial rate and contractile force at doses of 0.01-10 nmol but the responses to over 10 nmol of mabuterol gradually decreased and mabuterol at higher doses induced biphasic cardiac responses , i.e. , negative followed by positive cardiac responses .
C0018792
atrial
C0018787
cardiac