On the mechanism of slow calcium channel block in heart.

摘要: 1. D600 (methoxyverapamil, 2×10−6 M) has little activity when it is applied during a rest interval. Its ability to depress Isi and contraction much reduced the muscle rested. 2. Upon each activation blockade of slow channel increases until use-dependent increase equals diastolic removal, thus resulting in frequency-dependent steady-state blockade. 3. Removal block variable interval at various holding potentials faster more negative potential gets slower positive range. This process can be described by two voltage-dependent time constants (τ1, τ2).