two dihydropyridine compounds , bay k8644 ( a calcium entry activator ) and nifedipine ( a calcium entry blocker ) , were found to inhibit the binding of [ 3h ] phenylisopropyladenosine ( [ 3h ] pia ) to a1 adenosine receptors in rat cerebral cortex membranes with comparable potencies ( ic50 10-30 microm ) .
C0012315
dihydropyridine
C0028066
nifedipine