Effects of L-type Ca2+ channel modulation on direct myocardial effects of diazepam and midazolam in adult rat ventricular myocytes

Our objective was to determine whether an L-type Ca2+ channel modulation could alter myocardial depression induced by midazolam or diazepam in adult rat ventricular myocytes. Freshly isolated rat ventricular myocytes were loaded with fura-2/AM and field-stimulated (0.3 Hz) at 28°C. Amplitude and timing of intracellular Ca2+ concentration ([Ca2+]i) and myocyte shortening were simultaneously monitored in individual cells. Midazolam (3–100 µM)...