Question

A 45-year-old man presents for the evaluation of weight gain. He has noticed a 20-lb weight gain in the past few months without any change in his diet or activity level. He has started developing "stretch marks" on his abdomen as well. His wife has noted that even his face seems to be "growing fatter." Review of systems is significant for complaints of fatigue, multiple recent upper respiratory infections, and the development of facial acne. He has no significant medical history and takes no medications. There is a family history of diabetes and hypertension. On examination, his blood pressure is elevated at 165/95 mm Hg, but his other vital signs are normal. His face is plethoric, and he has a small fatty hump developing on his upper back. His abdomen is obese but soft and nontender without masses or fluid. Skin examination is notable for moderate facial acne and multiple violaceous striae on the abdomen. Blood tests show an elevated glucose level of 150 mg/dL, normal electrolytes, and renal function. His thyroid function tests are normal. You suspect idiopathic Cushing disease and order a dexamethasone suppression test to assist with confirming the diagnosis.

Which pituitary hormone stimulates the release of adrenocortical steroids?
What is the major glucocorticoid produced in the adrenal glands?
What is the major mineralocorticoid produced in the adrenal glands?
What is the major effect of mineralocorticoids?

Answer 1

Adrenocorticotropic Hormone (ACTH) stimulates the release of adrenocortical steroids. The major glucocorticoid is cortisol, while the major mineralocorticoid is aldosterone, which regulates blood pressure by affecting sodium and potassium balance.

Step-by-step explanation:

The 45-year-old man's symptoms suggest Cushing's syndrome, a condition characterized by the hypersecretion of cortisol. In his case, the suspicion of idiopathic Cushing's disease, which is often due to a pituitary adenoma, is reasonable. It is the pituitary hormone Adrenocorticotropic Hormone (ACTH) that stimulates the release of adrenocortical steroids. The major glucocorticoid produced in the adrenal glands is cortisol, which influences glucose metabolism and immune responses among other functions. The major mineralocorticoid produced in the adrenal glands is aldosterone, which mainly acts to regulate the balance of salt and water in the body, affecting blood pressure.

The major effect of mineralocorticoids like aldosterone is the regulation of sodium and potassium balance in the blood, promoting sodium retention, and potassium excretion by the kidneys, and indirectly affecting water retention, blood volume, and blood pressure.