depolarization with high k+ induced a [ ca2+ ] i rise ( revealed by the fura-2 fluorimetric technique ) that consisted of an initial ( 0.5-1 min ) peak followed by a prolonged ( several minutes ) plateau phase . omega-conotoxin blocked mainly the first phase , while the dihydropyridine ca2+ channel blocker , nitrendipine , primarily affected the plateau .
C0012315
dihydropyridine
C0028127
nitrendipine