Figure 3.

After 60 min of incubation, glucose-6-phosphate reduces the accumulation of ⁴⁵Ca²⁺ in brain ER microsomes. Addition of glucose-6-phosphate (10 mM), thapsigargin (1 μM), or the two in combination significantly reduced (p < 0.05) calcium accumulation. Individually, glucose-6-phosphate and thapsigargin reduced calcium accumulation by approximately 50%. When the two treatments were combined, there was no additive effect. Data are means ± SEM for n = 5. Each microsomal preparation contained a minimum of eight whole brains pooled together. ^abMeans with differing superscripts are significantly different, p < 0.05, while means that share superscripts are not significantly different.