ADMS 3502 Lecture Notes - Lecture 48: Voltage-Dependent Calcium Channel, Bk Channel, Cardiac Action Potential
21 May 2020
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Document Summary
After peak depolarization and inactivation, it returns to the open state and increases conductance when cell repolarizes at the end of a cardiac action potential. Investigated as a potential target for long q-t syndrome. There are several small molecule inhibitors of kv11. 1, and dofetilide is an antiarrythmic drug that blocks kv11. 1. It preferentially binds to the closed state and stabilizes the closed state-we reduce the number of channels that open on depolarization and this reduces overall kv11. 1 current. Bk channels are large-conductance, voltage and ca2+ activated k+ channels. They"re the largest of the k+ channels and have single channel conductance that approaches miniature synaptic events. Contribute to hyperpolarization after action potential and ca2+ entry. They have smaller conductance than the bk channels. Tetrameric k+ channel with a very large intracellular c-terminal. Two regulators of k+ conductance sites 1 and 2 impart ca2+ sensitivity.
