Cardiac mechanisms of norepinephrine Na(le) ACh N。rEp Muscarinic Beta-1 Receptor Receptor G G Stimulate Stimulates K Inhibition Cyclic-AMP
Cardiac mechanisms of norepinephrine
Mechanisms of norepinephrine -increase Nat cazt permeability 个, phase4 spontaneous depolarization个, autorhythmicity↑ Ca2 influx↑, phase0 amplitude& velocity个, conductivity个 Ca2 influx个,Ca2 release↑,[Ca2+]个, contractility个
Mechanisms of norepinephrine —increase Na+ & Ca2+ permeability • I f , phase 4 spontaneous depolarization, autorhythmicity • Ca2+ influx , phase 0 amplitude & velocity , conductivity • Ca2+ influx , Ca2+ release , [Ca2+ ] i , contractility
Asymmetrical 899t0 innervation of sympathetic nerve 59E Time(min)
Asymmetrical innervation of sympathetic nerve
Cardiac mechanisms of acetylcholine Na Ach NorEpi Muscaria Beta-1 Receptor Receptor G Stimulates Stimulates Inhibition Cyclic-AMP
Cardiac mechanisms of acetylcholine
Mechanisms of acetylcholine -increase K& decrease Ca permeability K+ outward↑,MRP|↑, phase4 spontaneous depolarization \, autorhythmicity l Inhibition of Caz+ channel, phase 0 amplitude velocity \, conductivity l Ca2+ influx V, [Ca2+]V, contractility t
Mechanisms of acetylcholine —increase K+ & decrease Ca2+ permeability • K+ outward , |MRP| , phase 4 spontaneous depolarization , autorhythmicity • Inhibition of Ca2+ channel, phase 0 amplitude & velocity , conductivity • Ca2+ influx , [Ca2+ ] i , contractility