Abstract: AIM: To study the effects and mechanisms of anisodamine on calcium transient and contractile function in isolated adult rat ventricular myocytes. METHODS: Single cell edge motion detection system and dual-excitation fluorescence photomultiplier system were used for measuring the intracellular calcium transient properties and contractile function. ΔFR, TTP, T₅₀ D, PS, TPS, TR₉₀ and ± d_L /d_t were recorded by the ionoptix system. Antagonist of IP₃ receptor, VDCC and muscarinic receptors were used for study the mechanism of anisodamine. RESULTS: Anisodamine (1 ×10^-9, 1 × 10^-7, 1 ×10^-5 mol·L^-1) directly inhibited intracellular calcium transient and contractile function. Carbachol (1 ×10^-6 mol·L^-1) abolished the effect of anisodamine. Heparin (1 ×10^-6 mol·L^-1) and verapamil (1 ×10^-6 mol·L^-1) decreased the effect of anisodamine. CONCLUSION: The effect of anisodamine on intracellular calcium transient and contractile function may be related to inhibition of calcium releasing from intracellular calcium pool and VDCC.

Key words: anisodamine, calcium transient, contraction, muscarinic receptor, VDCC