title: Isolation and characterization of a fraction from brain that inhibits 1,4-[3H]dihydropyridine binding and L-type calcium channel current.
abstract: Bovine brain was subjected to acid extraction and several purification steps. A fraction from brain that eluted from C18 reverse-phase columns at 30-35% acetonitrile inhibited [3H]nitrendipine binding to cardiac membranes. Further purification of this fraction on a sizing column in the presence of 40% acetonitrile yielded a low molecular mass fraction (less than 1 kDa) that produced a time- and voltage-dependent inhibition of L-type (but not T-type) Ca2+-channel current in GH3 cells. The results suggest that this fraction contains an endogenous substance that binds directly to slowly-inactivating Ca2+ channels and thereby inhibits current flow.
authors.affiliation: Institute for Preclinical Pharmacology, Miles Inc., West Haven, CT 06516.
authors.forename: R A
authors.initials: RA
authors.lastname: Janis
authors.forename: A V
authors.initials: AV
authors.lastname: Shrikhande
authors.forename: D E
authors.initials: DE
authors.lastname: Johnson
authors.forename: R T
authors.initials: RT
authors.lastname: McCarthy
authors.forename: A D
authors.initials: AD
authors.lastname: Howard
authors.forename: R
authors.initials: R
authors.lastname: Greguski
authors.forename: A
authors.initials: A
authors.lastname: Scriabine
mesh_terms: D000818:Animals; D001921:Brain / Q000502:physiology*; D002121:Calcium Channel Blockers / Q000378:metabolism*; D015220:Calcium Channels / Q000502:physiology*; D002417:Cattle; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D008564:Membrane Potentials / Q000187:drug effects; D009206:Myocardium / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000302:isolation & purification* / Q000494:pharmacology; D009568:Nitrendipine / Q000378:metabolism*; D011978:Receptors, Nicotinic / Q000187:drug effects / Q000378:metabolism*; D012016:Reference Values
chemical_list: D002121:Calcium Channel Blockers; D015220:Calcium Channels; D009419:Nerve Tissue Proteins; D011978:Receptors, Nicotinic; D009568:Nitrendipine