soterenol was analyzed as a competitive antagonist of isoproterenol-induced responses and the apparent dissociation constants ( ka ) for soterenol calculated to be 1.21 x 10 ( -7 ) m for receptors mediating positive chronotropic responses , 3.56 x 10 ( -7 ) m for receptors mediating positive inotropic responses , and 2.96 x 10 ( -7 ) m for receptors mediating increases in cyclic amp levels .
C0022245
isoproterenol
C1372804
positive chronotropic