Figure 4.

Glucose-6-phosphate reduces SERCA activity, as quantified by the release of inorganic phosphate from rat brain ER microsomes, in comparison to control. Glucose-6-phosphate significantly reduced (p < 0.05) the release of inorganic phosphate from brain ER microsome preparations after incubation for 6 min. However, the decrease in SERCA activity was not as great as that observed with the addition of thapsigargin (1 μM), a known potent, irreversible SERCA inhibitor. Treatment by both glucose-6-phosphate and thapsigargin did not further reduce accumulation below that of thapsigargin alone. Data are means ± SEM for n = 7. ^abcMeans with differing superscripts are significantly different, p < 0.05, while means that share superscripts are not significantly different.