Transport Proteins and Mutations

Question 1

T or F. Blood pressure is normal in both Bartter’s and Gitelman’s disease

Answer 1

T.

Question 2

What are the similarities in the way that Bartter’s and Gitelman’s present?

Answer 2

• hypokalemia
• metabolic alkalosis
• high PRA/ald activity
• normal BP

Question 3

How are Bartter’s and Gitelman’s differentiated clinically?

Answer 3

Batter’s is associated with hypercalciuria and Gitelman’s with hypocalciuria

Question 4

How does Liddle’s syndrome present?

Answer 4

• HTN
• hypokalemia
• suppressed PRA/ald activity

Question 5

A 28-year-old healthy asymptomatic 60 kg female has a normal physical examination. Blood pressure is 120/80 mm HG. Heart rate is 64 beats per minute. There is no edema. Serum sodium concentration is 140 mEq/L and urinary sodium concentration is

Answer 5

b) she has been ingesting a low sodium diet

Question 6

50-year-old male with chronic kidney disease as a blood pressure of 150/98 mm Hg and a small amount of ankle edema. Serum creatinine is 2.5 mg/dl. Serum sodium concentration is 140 mEq/l. Which of the following best describes the respective changes in total body water (TBW), intracellular fluid volume (ICFV), and extracellular fluid volume (ECFV)?

TBW, ICFV, ECFV

a) increased increased increased
b) increased normal/unchanged increased
c) normal/unchanged normal/unchanged increased
d) normal/unchanged increased normal/unchanged

Answer 6

b) increased normal/unchanged increased

Question 7

Previously healthy 60-year-old female has required continuous nasogastric suction for 72 hours following an exploratory laparotomy for appendicitis. Intake has consisted of approximately 2.5 liters per day of intravenous fluids consisting of 5 percent dextrose. Blood pressure has been stable at 130/70 mm Hg. There is no edema. Which of the following perturbations are most likely to be present?

a) metabolic alkalosis and hyperkalemia
b) metabolic alkalosis and hypokalemia
c) metabolic acidosis with normal plasma anion gap
d) metabolic acidosis with increased plasma anion gap
e) metabolic alkalosis and hypernatremia

Answer 7

b) metabolic alkalosis and hypokalemia

Question 8

A patient states he was treated with a diuretic by his local physician, but he cannot recall the drug’s name. Plasma chemistries include the following: sodium, 140 mEq/l, potassium 5.8 mEq/l, chloride 104 mEq/l, bicarbonate 24 mEq/l, blood urea nitrogen 10 mg/dl and serum creatinine 1.0 mg/dl. Which of the following is the most likely diuretic he was taking?

a) thiazide
b) spironolactone
c) loop diuretic, furosemide
d) vasopressin antagonist
e) osmotic diuretic, mannitol

Answer 8

b) spironolactone

Question 9

30-year-old female has severe hypertension and persistent hypokalemia. Multiple family members have had a similar presentation. Workup of family members has demonstrated renal potassium wasting, normal adrenal glands, suppressed plasma renin activity, and suppressed plasma aldosterone concentrations. These findings could best be accounted for by which of the following single gene mutations?

a) inactivating mutation of the sodium channel in the cortical collecting duct
b) inactivating mutation in the electroneutral NaCl transporter in the distal convoluted tubule
c) activating mutation of the sodium channel in the cortical collecting duct
d) inactivating mutation in the NaK2Cl transporter in the thick descending limb of the loop of Henle
e) inactivating mutation in carbonic anhydrase in the proximal convoluted tubule

Answer 9

c) activating mutation of the sodium channel in the cortical collecting duct