Robert Furchgott 1. muscarinic actions (cardiovascular system vessel dilation,BP↓( reflective HRT)HR↓ a. NO release↑ (M3R→EDRF(NO)↑→GC→cGMP↑→ intracellular Ca2) b. NA release .o Heart depression: atrium>ventricles negative(chronotropic, dromotropic, inotropic) effect Direct effect: mainly in atrium Indirect effect (negative feedback NA release D): ventricles1. muscarinic actions (1) cardiovascular system ❖ vessel dilation, BP↓ (reflective HR↑) HR a. NO release↑ (M3 R →EDRF(NO) ↑→GC →cGMP↑→ intracellular Ca2+↓) b. NA release↓ ❖ Heart depression: atrium>ventricles negative (chronotropic, dromotropic, inotropic) effect Direct effect: mainly in atrium Indirect effect (negative feedback NA release ↓): ventricles Robert Furchgott