High-affinity antibodies specific for the 1,4-dihydropyridine Ca 2+ channel blockers have been produced in sheep and affinity purified using a dihydropyridine-Sepharose affinity column. Dihydropyridine-Sepharose affinity matrix was synthesized by reaction of aminohexyl-Sepharose with an affinity analogue of nifedipine, dimethyl l,4-dihydro-2,6-dimethyl-4-(2-isothiocyanatophenyl)-3,5-pyridinedicarboxylate. Residual amine groups were then blocked by carbodiimide-catalyzed acetylation. channels is important in mediation of contraction in cardiac and smooth muscle
