title: Isolation of synaptic vesicles from Narcine brasiliensis electric organ: some influences on release of vesicular acetylcholine and ATP.
abstract: A simple density gradient centrifugation technique for separating electric organ cholinergic synaptic vesicles from other organelles and membrane fragments is described. Frozen, ground electric organ is extracted with a solution of similar density to the vesicles; during the subsequent centrifugation, vesicles remain suspended in the extraction medium and heavier contaminating structures sediment out. In confirmation of results obtained with mammalian central nervous system vesicles, a biphasic pattern of efflux of bound ACh is demonstrated. Low levels of phospholipase A2 (EC 3.1.1.4.) induce efflux of ACh from the vesicle fraction; it is shown that the concomitant fall in vesicle bound ATP is due to ATP efflux rather than ATP hydrolysis within the vesicle.
mesh_terms: D000109:Acetylcholine / Q000032:analysis / Q000378:metabolism*; D000110:Acetylcholinesterase / Q000032:analysis; D000255:Adenosine Triphosphate / Q000032:analysis / Q000378:metabolism*; D000818:Animals; D004557:Electric Organ / Q000187:drug effects / Q000378:metabolism*; D005399:Fishes / Q000378:metabolism*; D008244:Lysophosphatidylcholines / Q000494:pharmacology; D010740:Phospholipases / Q000494:pharmacology; D013385:Succinate Dehydrogenase / Q000032:analysis; D013572:Synaptic Vesicles / Q000032:analysis / Q000187:drug effects / Q000378:metabolism*; D013696:Temperature
chemical_list: D008244:Lysophosphatidylcholines; D000255:Adenosine Triphosphate; D013385:Succinate Dehydrogenase; D010740:Phospholipases; D000110:Acetylcholinesterase; D000109:Acetylcholine