Pharmacology The neurotransmitter agent that is normally released in the SA node of the heart in response to increased blood pressure is: A Acetylcholine B Dopamine C Adrenaline D Noradrenaline 💡 Explanation The neurotransmitter agent that is normally released in the SA node of the heart in response to increased blood pressure is: ✓ Correct Answer: A. Acetylcholine