A patient complains of excessive urine output and constant thirst. Laboratory tests show an elevated plasma sodium concentration (151 mEq/L) and elevated plasma osmolality (320 mOsm/L). The urine osmolality is only 75 mOsm/L. Which of the following could explain the patient's problem? A) Defective epithelial sodium channel (ENaC) B) Defective ROMK proteins C) Defective V₂ receptor proteins D) Excessive antidiuretic hormone (ADH) secretion E) Defective atrial natriuretic peptide (ANP) secretion

Question

Quizplus · Accepted Answer

The symptoms and lab results suggest diabetes insipidus, characterized by an inability to concentrate urine despite high plasma osmolality. This is often due to defective V2 receptor proteins, which are responsible for the action of ADH in the kidneys.

A Patient Complains of Excessive Urine Output and Constant Thirst