these results support the hypothesis that m1 muscarinic coronary receptors are responsible for the redistribution of blood flow to the subendocardium ( increased endocardial to epicardial blood flow ratio ) during cholinergic coronary vasodilatation , whereas both m1 and m2 receptors are involved in increasing myocardial perfusion .
C0034826
muscarinic
C0384752
m2 receptors