title: An antibody to dihydropyridine calcium entry blockers. A comparison with the calcium channel receptor in skeletal muscle.
abstract: Antibodies that recognize dihydropyridine (DHP) calcium entry blockers were elicited from rabbits. A sensitive and specific radioimmunoassay for dihydropyridines was developed and its specificity compared to the DHP binding site in skeletal muscle membranes. The antibody bound [3H]nitrendipine with a higher affinity (KD = 0.155 nM) than did the DHP receptor of skeletal muscle (KD = 1-3 mM); however, in contrast to the DHP receptor, the antibody recognized only those DHP drugs with meta-nitrophenyl substituents at the 4-position on the DHP ring. Both the antibody and receptor exhibited stereospecificity, with each site recognizing the (+)-isomer of nicardipine as the more potent. This antibody should prove useful in our studies of some potentially irreversible DHP molecules.
mesh_terms: D000906:Antibodies / Q000276:immunology*; D000915:Antibody Affinity; D000918:Antibody Specificity; D000941:Antigens / Q000276:immunology; D002121:Calcium Channel Blockers / Q000276:immunology*; D015220:Calcium Channels; D055598:Chemical Phenomena; D002621:Chemistry; D004095:Dihydropyridines; D006241:Haptens / Q000276:immunology; D009132:Muscles / Q000032:analysis*; D009568:Nitrendipine / Q000276:immunology; D011725:Pyridines / Q000276:immunology*; D011978:Receptors, Nicotinic / Q000276:immunology*
chemical_list: D000906:Antibodies; D000941:Antigens; D002121:Calcium Channel Blockers; D015220:Calcium Channels; D004095:Dihydropyridines; D006241:Haptens; D011725:Pyridines; D011978:Receptors, Nicotinic; C038806:1,4-dihydropyridine; D009568:Nitrendipine