the regional concentrations of dopamine , serotonin , dihydroxyphenylacetic acid , homovanillic acid and 5-hydroxyindole acetic acid were measured in mouse brain following administration of the dihydropyridine calcium channel activator bay k 8644 , and antagonist , nifedipine .
C0012315
dihydropyridine
C0028066
nifedipine