Figure 9.

The removal of extracellular Ca²⁺ hindered the berberine-induced increase in the intracellular Ca²⁺ level of freshly isolated LV myocytes. (A–D) Original Ca²⁺ imaging recordings of the LV myocytes treated with vehicle (A) and 300 μM berberine (B); vehicle (C) and 300 μM berberine (D) in the Ca²⁺-free modified Krebs-Hensseleit (K-H) buffer, respectively. (E) Summary data showing that the removal of extracellular Ca²⁺ significantly hindered the 300 μM berberine-induced increase in the intracellular Ca²⁺ level of LV myocytes. The numbers of repeats are as follows: vehicle control of 300 µM Ber, n = 57, N = 3; 300 µM Ber, n = 83, N = 3; vehicle control of 300 µM Ber in the Ca²⁺-free modified K-H buffer, n = 27, N = 3; 300 µM Ber in the Ca²⁺-free modified K-H buffer, n = 47, N = 3; n and N are the numbers of LV myocytes and rats, respectively. Ber stands for berberine. ***p < 0.001 vs. vehicle control group; ^###p < 0.001 vs. Ber-treated group in the normal modified K-H buffer; two-way ANOVA with Tukey's multiple comparisons test.