Figure 11.

The berberine-induced tension increase in left ventricular muscle (LVM) strips was extracellular Na⁺-dependent. (A, B, D) Original isometric tension recordings of the LVM strips treated with 300 μM berberine (A), and 300 μM berberine under the low Na⁺ condition where NaCl of the Krebs-Hensseleit (K-H) buffer was replaced with CsCl (B) or with NMDG (D). (C, E) Summary data indicating that the 300 µM berberine-induced tension increase has a positive correlation with the concentrations of extracellular NaCl. The numbers of repeats are as follows: experiments with the normal K-H buffer, 300 µM Ber, n = 6, N = 6. Experiments with the K-H buffer in which NaCl was replaced with CsCl: 300 µM Ber in the buffer containing 77 or 10 mM NaCl, n = 5, N = 5; 300 µM Ber in the buffer containing 0 mM NaCl, n = 6, N = 6. Experiments with the K-H buffer in which NaCl was replaced with NMDG: 300 µM Ber in the buffer containing 77 or 0 mM NaCl, n = 6, N = 6; 300 µM Ber in the buffer containing 10 mM NaCl, n = 5, N = 5. n and N are the numbers of LVM strips and rats, respectively. Ber stands for berberine. ***p < 0.001 vs. vehicle control group; ^#p < 0.05, ^##p < 0.01, ^###p < 0.001 vs. Ber-treated group in the normal K-H buffer; two-way ANOVA with Tukey's multiple comparisons test.