Figure 7.

Effects of low and high concentrations of capsaicin on the simulated action potentials, intracellular Ca²⁺ transients, and force development during a single twitch response using LabHEART simulations. (A) At 10 µM capsaicin concentrations, the inhibition of I_Kr, I_Ks, I_to was incorporated. Whereas, at 30 µM capsaicin concentrations inhibitions of I_Kr, I_Ks, I_to, I_K1, I_Na, and I_Ca-L were incorporated into the model. At 10 µM concentration, capsaicin induced marked prolongation (39%) of APD₅₀, while at higher concentration (30 µM) significantly shortened (27%) the APD₅₀. (B) Capsaicin, at the concentration of 10 µM, caused a slight delay in decay phase of Ca²⁺ transient. At higher concentration of 30 µM, capsaicin induced a marked suppression of Ca²⁺ transient. (C) Capsaicin, at 10 µM concentrations, caused a slight delay in decay phase of force development, but at higher concentrations of 30 µM, capsaicin induced a marked inhibition of force development during a simulated twitch response of a rabbit ventricular cardiomyocyte.