Key Points
- This research investigates how specific inhibitors affect the systolic calcium transient in rat ventricular myocytes.
- Examined effects of thapsigargin (1-10 µM), ryanodine (1-10 µM), and caffeine (0.5-10 mM) on indo-1-loaded rat ventricular myocytes.
- Measured changes in calcium transient magnitude and rate of decay for each inhibitor.
- Used a model to reproduce results based on the effects on sarcoplasmic reticulum calcium content.
- Thapsigargin decreased the calcium transient magnitude and slowed decay more than the other agents.
- Ryanodine also decreased the transient magnitude but showed no initial change in decay rate.
- Caffeine decreased both magnitude and decay rate, with graded effects based on concentration.
Structured PICO
PPopulationindo-1-loaded rat ventricular myocytes
IInterventionThapsigargin (1-10 microM), ryanodine (1-10 microM), and caffeine (0.5-10 mM)
OOutcomemagnitude and rate of decay of systolic Ca2+ transientssurrogate
Inhibitors of sarcoplasmic reticulum function decrease the magnitude of systolic Ca2+ transients in rat ventricular myocytes by reducing SR calcium content, with varying effects on the rate of decay.