Research Article

Effects of Hyperglycemia on Vascular Smooth Muscle Ca2+ Signaling

Figure 5

Effect of glucose on Ca2+ leak and Ca2+ extrusion in A7r5 VSM cells. A7r5 cells, cultured under HG, NG, and OC, were loaded with Fura2-AM and passive leak was monitored after store depletion with 1 μM thapsigargin (TG), an irreversible SERCA inhibitor (a). Peak amplitude in response to TG (TG max release) and the time to maximum release are shown (b, c). Ca2+ extrusion, which is presumed to be due to the combined activity of PMCA and NCX, was monitored as the decay of the TG-induced Ca2+ transient in Ca2+ free conditions to avoid Ca2+ influx. To inhibit NCX, sodium was replaced with equimolar concentration of N-methyl-D-glucamine (d-e). Time to half () decay was then measured and compared between the different conditions (d-e). Data are presented as mean ± SE from at least three independent experiments done each in triplicate. .
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