Figure 12.

The berberine-induced increase in the intracellular Ca²⁺ level of left ventricular (LV) myocytes was extracellular Na⁺-dependent. (A–D) Original Ca²⁺ imaging recordings of the LV myocytes treated with vehicle (A) and 300 μM Ber (B); vehicle (C) and 300 μM Ber (D) in the modified Krebs-Hensseleit (K-H) buffer containing 62.5 mM NaCl and 62.5 mM NMDG, respectively. (B) Summary data indicating that the berberine-induced increase in the intracellular Ca²⁺ level in a buffer containing 62.5 mM NaCl was smaller than that in a buffer containing 125 mM NaCl. The numbers of repeats are as follows: vehicle control of 300 µM Ber, n = 42, N = 3; 300 µM Ber, n = 58, N = 3; vehicle control of 300 µM Ber in the K-H buffer containing 62.5 mM NaCl, n = 24, N = 3; 300 µM Ber in the K-H buffer containing 62.5 mM NaCl, n = 21, 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 modified K-H buffer containing 125 mM NaCl; two-way ANOVA with Tukey's multiple comparisons test.