Which of the following enzyme is inhibited by Aminophylline –
**Core Concept**
Aminophylline is a bronchodilator medication that belongs to the class of xanthines. It is a phosphodiesterase inhibitor, which affects the levels of cyclic adenosine monophosphate (cAMP) within the cell.
**Why the Correct Answer is Right**
Aminophylline exerts its bronchodilatory effects by inhibiting the enzyme phosphodiesterase (PDE), specifically PDE3 and PDE4. By inhibiting PDE, aminophylline increases the levels of cAMP within the cell, leading to relaxation of smooth muscle cells in the airways. This results in bronchodilation and improved lung function.
**Why Each Wrong Option is Incorrect**
* **Option A:** Phospholipase C is not directly related to the mechanism of action of aminophylline.
* **Option B:** Acetylcholinesterase is an enzyme involved in the breakdown of acetylcholine, and its inhibition would have opposite effects to aminophylline.
* **Option D:** Glycogen phosphorylase is an enzyme involved in glycogenolysis, and its inhibition is not related to the mechanism of action of aminophylline.
**Clinical Pearl / High-Yield Fact**
Aminophylline is often used in combination with other medications, such as beta-agonists, to enhance its bronchodilatory effects. However, it is essential to monitor patients for potential side effects, including cardiac arrhythmias and seizures.
**Correct Answer:** C. Phosphodiesterase.