Ca2+ channels from brain microsomal membranes reconstituted in patch-clamped bilayers.
Single Ca2+ channels from brain microsomal membranes were reconstituted in bilayers made at the tips of patch-clamp micropipettes. The single-channel conductance was defined to be 107 pS in 50 mM Ca2+. The channel activity was stimulated by nucleotides and inositol 1,4,5-trisphosphate (Ins-P3), and was inhibited by ruthenium red. Na+ added asymmetrically to the membrane bilayer induced an increase in the Ca2+-channel activity. The described characteristics of these Ca2+ channels suggest that they may be responsible for the Ca2+ transport across the membranes of the endoplasmic reticulum system triggering and modulating various neurosecretory and excitatory processes in nerve cells.
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000648:ultrastructure; D001923:Brain Chemistry; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D002417:Cattle; D004553:Electric Conductivity; D007425:Intracellular Membranes / Q000032:analysis; D007473:Ion Channels / Q000032:analysis*; D008051:Lipid Bilayers / Q000032:analysis*; D008861:Microsomes / Q000032:analysis*; D012964:Sodium / Q000494:pharmacology
D002121:Calcium Channel Blockers; D007473:Ion Channels; D008051:Lipid Bilayers; D000255:Adenosine Triphosphate; D012964:Sodium; D002118:Calcium