Fig. 3.
Hyperforin induced an elevation of intracellular Ca2+ concentration. Incubation of flexor digitorum brevis muscle fibers isolated from wild-type, wild-type/dominant-negative transient receptor potential canonical 6 (TRPC6), RYR1-p.R163C, and RYR1-p.R163C/dominant-negative TRPC6 mice with 10 µM hyperforin produced a statistically significant (P < 0.0001) increase in intracellular Ca2+ concentration in all genotypes, but the effect was more marked in RYR1-p.R163C fibers than in wild type. Expression of dominant-negative TRPC6 in wild type and RYR1-p.R163C reduced the effect of hyperforin. The experimental conditions used are indicated on the horizontal axis. For intracellular Ca2+ concentration measurements: Five mice per genotype, wild-type, 19 cells; wild-type dominant-negative TRPC6, 20 cells; RYR1-p.R163C, 22 cells; RYR1-p.R163C/dominant-negative, TRPC6 20 cells. The values are expressed as means ± SD for each condition. Statistical analysis was done using a one-way ANOVA with Tukey’s posttest. *P ≤ 0.05.