Final answer:
Nitrates such as nitroglycerine treat angina by releasing nitric oxide (NO), which dilates blood vessels and improves blood flow to reduce chest pain associated with angina pectoris.
Step-by-step explanation:
Nitrates help treat angina pectoris by facilitating the dilation of blood vessels, which can improve blood flow to the heart muscle and reduce chest pain. When someone experiences angina, it is often due to a partial blockage of the coronary arteries, which decreases oxygen supply to the heart, leading to pain.
Nitrates like nitroglycerine work by releasing nitric oxide (NO), a potent vasodilator, which relaxes the smooth muscle in the vessel walls, particularly in the tunica media of coronary vessels. This dilation increases the diameter of the vessels and therefore decreases the pressure with which the blood flows through, easing the heart's workload and alleviating the pain caused by angina. This effect can be immediate if nitroglycerine is administered sublingually, providing rapid relief during an angina attack.