Question

We know that angiotensin II (ANG II) has effects on multiple tissues and, as such, the ACE inhibitor captopril would have several consequences. Select TWO ways that captopril can manage Mimi's high blood pressure. It inhibits the release of anti-diuretic hormone (ADH) and increases water excretion in urine. It decreases aldosterone release, decreases Na+ reabsorption from the principal cells and promotes water excretion. It increases Na+ reabsorption in the proximal convoluted tubule (PCT). It vasodilates arterioles and increases total peripheral resistance (TPR). It increases thirst

Answer 1

Question 1

Options 2 (It decreases aldosterone release, decreases Na⁺ reabsorption from the principal cells and promotes water excretion) and 5 (It increases thirst) are correct.

Justification:

Option 2: For managing high blood pressure i.e., lowering the high blood pressure, lower levels of aldosterone may experience low blood pressure, which can be possible with captopril. Captopril acts by decreasing the reabsorption of Na⁺ (sodium) in the proximal convoluted tubules (PCT) and it also promotes water excretion, which helps in managing the high blood pressure. So, option 2 is correct.

High blood pressure or hypertension can be common due to dehydration. So, to manage high blood pressure, increase in thirst is a condition, which can be achieved by captopril. So, option 5 is correct.

Justification for incorrect options:

• Option 1 is incorrect because anti-diuretic hormone (ADH) helps to control blood pressure by acting on kidneys and blood vessels and its inhibition causes increase in blood pressure. As the given option is inhibition of the release of anti-diuretic hormone (ADH), it is incorrect.
• Option 3 is incorrect because increase in Na⁺ (sodium) reabsorption increases blood pressure.
• Option 4 is incorrect because increase in total peripheral resistance (TPR) increases blood pressure.

Question 2

Option 5 (Captopril = ↓ACE activity = ↓angiotensin II formation = ↓Na⁺ reabsorption in the proximal convoluted tubule =↑Na⁺ and water excretion in urine = ↓blood volume and ↓blood pressure) is correct.

Justification: Because captopril belongs to a class of medicines called 'angiotensin-converting enzyme inhibitors'. So, it decreases ACE activity. It thereby decreases angiotensin II formation. Angiotensin II inhibition causes decreased sodium reabsorption and increased sodium and water excretion in urine. This ultimately decreases blood pressure and volume. So, option 5 is correct.

Thank you!