effect of ACh and adrenaline on heart rate
Acetylcholine (ACh) was a common neurotransmitter that for the synapses in the autonomic nervous system, mainly in the parasympathetic nerve towards the heart. ACh were expected to decrease the heart rate. The mechanism started with the ACh bound to the sacrolemma-related cholinergic muscarinic receptors, consisting £i, £] and £^ subunits. ... Besides, the £]-£^ complex opened the ACh-activated potassium channels. This decreased the rate of pre-potential formation and the hyperpolarization process to be slower, creating the bradycardia condition, the decrease in heart rate.