The action of nitroglycerin, as a heart medication, is related to NO production.
a.All three statements are true.
b.Two of the three statements are true.
c.Only one of the statements is true.
d.None of the statements is true.
The correct answer and explanation is :
Correct Answer:
a. All three statements are true.
Explanation:
Nitroglycerin is a widely used medication for treating angina (chest pain) and heart conditions like heart failure. Its effectiveness is due to its ability to release nitric oxide (NO) in the body, which leads to vasodilation—the widening of blood vessels. This process helps to reduce the heart’s workload and improve blood flow, relieving chest pain and preventing heart attacks.
Here’s how nitroglycerin works:
- Nitroglycerin is converted to nitric oxide (NO): Once in the body, nitroglycerin undergoes a chemical reaction that releases NO, a potent vasodilator.
- Nitric oxide activates guanylate cyclase: NO stimulates an enzyme called guanylate cyclase, leading to an increase in cyclic guanosine monophosphate (cGMP) levels inside blood vessel cells.
- Smooth muscle relaxation and vasodilation occur: cGMP causes the smooth muscles of blood vessels to relax, leading to dilation of veins and arteries. This reduces the oxygen demand of the heart and relieves angina symptoms.
Because all three statements about nitroglycerin’s connection to NO production, guanylate cyclase activation, and vasodilation are true, the correct answer is option A: All three statements are true.
This mechanism explains why nitroglycerin is a crucial medication for heart disease management, helping to prevent serious complications like myocardial infarction (heart attack). However, overuse can lead to tolerance, requiring careful dosing and monitoring by healthcare providers.