Does magnesium play a role in the hypokalemia of Bartter’s syndrome?
A patient with Bartter’s syndrome manifested hypomagnesemia in addition to hypokalemia. Under conditions of maximal free water production, he had a fractional distal solute reabsorption of 0.65, a value consistent with a renal defect in sodium chloride reabsorption in the thick ascending limb of the loop of Henle. This is also the site of 65% to 70% of urinary magnesium reabsorption.