A 50-year-old woman with hypertension (BP 168/104 mmHg, HR 88/min) is found to have a 2-cm adrenal adenoma on CT imaging producing elevated aldosterone (28 ng/dL; normal <16). Laboratory studies show hypokalemia (K+ 3.2 mEq/L) and metabolic alkalosis (HCO3− 32 mEq/L), with normal ACTH levels. She denies headaches or palpitations. Which of the following factors is the primary physiologic regulator of aldosterone secretion under normal conditions?
- A)Growth hormone
- B)Dopamine
- C)Thyrotropin releasing hormone
- D)ACTH from the anterior pituitary
- E)Angiotensin II and serum potassium concentrationGABARITO
Explicação
Aldosterone secretion from the zona glomerulosa is regulated mainly by angiotensin II and serum potassium, not by ACTH. This is why mineralocorticoid function is usually preserved in secondary adrenal insufficiency, where ACTH is low. First Aid style endocrine... Ver explicação completa e trilha adaptativa →