Possible Interaction: Acetylcholine and Quinine

“ Quinine (1 mM), inhibitor of organic cation transporters, and carnitine (0.1 mM), substrate of the Na+‐dependent carnitine transporter OCTN2, tended to reduce acetylcholine release (by 40%, not significant).”

“ Quinine , an inhibitor …), reduced acetylcholine release in a reversible and concentration‐dependent manner with an IC50 value of 5 μM. The maximal effect, inhibition by 99%, occurred at … μM. Procaine (100 μM), a sodium channel blocker, and vesamicol (10 μM), an inhibitor of the vesicular acetylcholine transporter, were ineffective.”

“Verapamil, apamin, …, quinine and charybdotoxin reduced the contractile responses induced by ACh and 5-HT in ileum from rabbits treated with SWCNTs, indicating that voltage-dependent Ca2+ channels and small, intermediate, and large-conductance Ca(2+)-activated, ATP-sensitive, and voltage-dependent K+ channels are involved in these effects.”

“Blockade of nicotine or muscarine receptors did not significantly modulate the release of acetylcholine which was substantially reduced by 300 μM quinine (inhibitor of organic cation transporters).”

“Block by chloroquine was purely competitive, whereas quinine inhibited ACh currents in a mixed competitive and noncompetitive manner.”

“… quinine (15-150 μM) into an adrenal … inhibition in CA secretion evoked by ACh (5.32 × 10-3M), high K+ (5.6 × 10-2M), DMPP (10-4 M for 2 min), McN-…), cyclopiazonic acid (10-5 M for 4 min) and Bay-K-8644 (10-5M for 4 min).”

“Inhibition of KCl release quinine , Ba2+, NPPB or KCl solution) suppressed both the exocytotic events and cell shrinkage evoked by ACh.”

“Although intraoral infusions of quinine or distilled water caused a significant increase in ACh in the parietal cortex, the magnitude of increased ACh was smaller than that in the gustatory cortex.”

“Among them, infusion of 0.001 M quinine HCl produced a marked increase in the release of ACh up to 355% of baseline levels.”

“Among the potassium channel blockers tested only quinine (at 0.5 or 1 mmol/l), in the same manner as lidocaine, reduced the evoked secretion of 3H-acetylcholine.”

“3 Pretreatment of the tissues with quinine (2.5 × 10−5 to 10−4 m) for 60 min produced a concentration‐dependent inhibition of the relaxation induced by ACh.”

“5 On a molar basis, quinine was more effective than the two tetraalkylammonium ions in reducing the endothelium‐dependent relaxations of the aortic strips induced by ACh or A23187.”

“… Quinine (10−4 m, 60 min), TMA (6.5 × 10−2 m, 90 min) or TEA (3 × 10−… m, 90 min) produced 5 to 10 fold reductions in the relaxant EC50 values of A23187 and ACh and depressed (by 40 to 95%) the … relaxations to the ionophore and ACh.”