title: Inhibition of [3H]acetylcholine active transport by tetraphenylborate and other anions.
abstract: The effects of tetraphenylborate and other anions on the active uptake of [3H]acetylcholine by synaptic vesicles isolated from Torpedo californica electric organ were studied. Tetraphenylborate completely inhibits active uptake with a half-inhibitory concentration of 0.3 microM. Dipicrylaminate also half-inhibits at 0.3 microM, phenyldicarbaundecaborane at 14 microM, fluoride at 2 mM, thiocyanate at 3 mM, and azide at 16 mM. Tetraphenylborate had no effect on the vesicle ATPase activity or the transmembrane electric potential at low concentrations where it inhibits [3H]acetylcholine active transport. The mechanism for tetraphenylborate inhibition is uncertain, but it might be similar to that of its action as a mitochondrial uncoupler. Solubility products for the acetylcholine, choline, and potassium salts of the tetraphenylborate and dipicrylaminate anions also were measured. The inhibition results confirm the hypothesis of Marshall and Parsons [Br. J. Pharmacol. 54:333-338 (1975)] that tetraphenylborate acts on intact neuromuscular preparations to inhibit transmitter storage, and constitute new pharmacological evidence that evoked release of acetylcholine is mediated by synaptic vesicles.
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D000838:Anions / Q000494:pharmacology*; D001693:Biological Transport, Active / Q000187:drug effects; D001896:Boron Compounds / Q000494:pharmacology*; D004557:Electric Organ / Q000378:metabolism; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D010851:Picrates / Q000494:pharmacology; D012995:Solubility; D013572:Synaptic Vesicles / Q000187:drug effects / Q000378:metabolism*; D013775:Tetraphenylborate / Q000494:pharmacology*; D014101:Torpedo
chemical_list: D000838:Anions; D001896:Boron Compounds; D010851:Picrates; C011454:dipicrylamine; D013775:Tetraphenylborate; D000109:Acetylcholine