Potent inhibitor of Ca²⁺/Mg²⁺ - ATPase.

Benzohydroquinone‚ C₁₄H₂₂O₂ ‚ synthetic.

Ca²⁺ mobilizer; the effect of BHQ is to inhibit Ca²⁺ sequestration by the stores and not to stimulate aCa²⁺ efflux pathway‚ suggesting that its inhibitory effects on microsomal Ca²⁺-ATPase probably underlie its effects on intracellular Ca²⁺ stores.[1] In permeabilized rat hepatocytes‚ a maximal concentration (25 µM) mobilized 70 % of sequestered Ca²⁺ and a half-maximal effect was produced by 1.7 µM.


Although BHQ has some selectivity for the Ca²⁺ transport system of Inositol 1‚4‚5-triphosphate (IP3) -sensitive stores‚ the selectivity is weak and BHQ mobilizes substantially more Ca²⁺ than does a maximally effective concentration of IP3.[1]

1. Oldershaw et al., "2,5-Di-(tert-butyl)-1,4-benzohydroquinone mobilizes inositol 1,4,5-triphosphate-sensitive and -insensitive Ca²⁺ stores" FEBS Lett., (1990). 274(1-2):214-216
2. Schilling et al., Biochem. J., (1992). 284:521
3. Moore et al., FEBS Lett. (1987). 224:331
4. Wictome et al., FEBS Lett. (1992). 304:109
5. Mason et al., J. Biol. Chem. (1991). 266:20856