Figure 8.

Effects of quercetin on the depolarization-induced rise in intracellular calcium in INS-1 cells. The intracellular Ca²⁺ concentration ([Ca²⁺]_i) was measured using the ratiometric fluorescent Ca²⁺ indicator fura-2. Typical cell images illustrating the change in fluorescence induced after addition of 15 mmol·L⁻¹ KCl (right panels) in absence (C) (upper panels) or presence (lower panels) of 20 µmol·L⁻¹ quercetin (Q) are presented (Figure 8A). Typical recording of the rise in [Ca²⁺]_i (fluorescence ratio F₃₄₀/F₃₈₀) after addition of 15 mmol·L⁻¹ KCl either under basal KRB condition (C) (upper panel) or after a 15 min pre-incubation period with quercetin 20 µmol·L⁻¹ (Q) (lower panel) is shown (Figure 8B). Time-course of the averaged response to 15 mmol·L⁻¹ KCl in the absence (KCl) or presence of 20 µmol·L⁻¹ quercetin (KCl + Q) is shown (Figure 8C). ***P < 0.001, significant difference between the values indicated.