bay k 8644 , a dihydropyridine of the nifedipine type , was shown to increase coronary resistance and to enhance myocardial contractility ( schramm et al. , nature 1983 ; 303:535-7 ) , in contrast to the well-known vasodilating and negative inotropic effects of the `` '' classical '' '' calcium channel blockers .
C0012315
dihydropyridine
C0028066
nifedipine