Inhibition of [3H]acetylcholine active transport by tetraphenylborate and other anions.
1983; American Society for Pharmacology and Experimental Therapeutics; Volume: 24; Issue: 1 Linguagem: Inglês
10.1016/s0026-895x(25)14415-5
ISSN1521-0111
AutoresD. C. Anderson, Steven C. King, Stanley M. Parsons,
Tópico(s)Electrochemical Analysis and Applications
ResumoThe 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.
Referência(s)