Renin-Angiotensin-Aldosterone System (RAAS)

A 58-year-old woman with resistant hypertension (BP 165/95 mmHg despite amlodipine 10 mg and metoprolol 100 mg daily) undergoes screening for secondary hypertension. Plasma renin activity is markedly suppressed (0.3 ng/mL/hr; normal: 0.5–1.6), and serum aldosterone is elevated at 18 ng/dL (normal: 3–10 supine). Abdominal CT shows a 1.2 cm left adrenal nodule. What is the most appropriate next step in management?

A 58-year-old Indian male with hypertension and type 2 diabetes mellitus is prescribed an ACE inhibitor for renal protection. After 3 weeks, he develops a persistent dry cough and mild facial swelling. On examination, there is no evidence of heart failure or infection. The structure marked **C** in the RAAS diagram is the target of which class of antihypertensive agents that would be most appropriate for this patient?

A 52-year-old man with newly diagnosed hypertension (BP 168/104 mmHg) and hypokalemia (K⁺ 3.2 mEq/L) presents to the clinic. Serum sodium is 148 mEq/L. Plasma renin activity is suppressed (0.3 ng/mL/hr; normal 0.5–1.6). Aldosterone level is elevated at 28 ng/dL (normal <15). The patient denies use of diuretics or licorice. What is the most appropriate next step in management?

A 38-year-old woman with a history of recurrent hypertensive crises, palpitations, and diaphoresis is suspected of having secondary hypertension due to pheochromocytoma. Which investigation is the most appropriate initial confirmatory test for this diagnosis?

Which is the most common site of renin synthesis and secretion in the kidney?