Possible Interaction: Quinacrine and Calcium Supplement

“There was apparently an increase in the cytoplasmic calcium concentration, which acted through calmodulin, since the histamine release induced by calcium from the permeabilized mast cells could be inhibited by a calmodulin-antagonist, mepacrine (10–30 μM).”

“Thus, the monensin‐mediated decrease in PKC activity seen without Ca was partially attenuated by pretreatment with quinacrine.”

“Thus, inhibition of PLA2 does not protect the myofilament apparatus against calcium released intracellularly, and it is suggested that mepacrine and indomethacin can block entry of calcium in the calcium-paradox in the amphibian heart.”

“Addition of 10(-3) M calcium affected the inhibition by amiloride (K0.5 = 1.02 x 10(-3) M, nH = 1.41) and quinacrine (K0.5 = 3.3 x 10(-5) M, nH = 0.65).”

“We conclude that calcium addition modulates the inhibitions by amiloride and quinacrine by increasing the inhibition constants and changing the cooperativity.”

“With calcium added the mechanisms of inhibitions were complex, allosteric, and could be explained by positive cooperativity between sites for amiloride and negative cooperativity between sites for guinacrine.”

“The ability of quinacrine to inhibit calcium was investigated further in cardiac ventricular myocytes.”

“In permeabilized acini, mepacrine shifted the dose-response curve for calcium to the right by a factor 2 and inhibited the release of amylase stimulated by GTPrS. From these results we conclude that carbachol, CCK-8 and GTPrS probably activate a phospholipase A2 closely coupled to exocytosis.”

“ Quinacrine almost completely suppresses calcium‐ and carbachol‐mediated AA release.”

“Our results suggest that mepacrine , NDHGA and indomethacin, independently of inhibition of eicosanoids synthesis, reduce the entry of extracellular calcium and/or the release of intracellular calcium.”

“The inhibition of depolarization induced calcium uptake by quinacrine was reduced by 70% after washing, whereas that by quinacrine mustard was not affected.”

“The depolarization‐induced uptake of calcium is inhibited 85% by 3 mM CoCl2 80% by 100μM quinacrine and 50% by 15μM trifluoperazine while these agents had little effect on the kainate‐induced uptake.”