A 52-year-old man presents for evaluation of resistant hypertension. Despite adherence to an ACE inhibitor and a calcium channel blocker, his blood pressure remains elevated. He denies muscle weakness or cramps. Physical examination is notable for blood pressure of 158/96 mm Hg and no peripheral edema. Laboratory studies reveal serum sodium 145 mEq/L (normal 135–145), potassium 2.8 mEq/L (3.5–5.0), bicarbonate 32 mEq/L (22–28), plasma renin activity suppressed, and plasma aldosterone concentration elevated. A CT scan demonstrates a unilateral adrenal adenoma. Which of the following cellular changes in the renal collecting duct best explains this patient’s clinical presentation?