Effect of parathyroid extract on magnesium excretion in man.

Abstract

Parathyroid extract, 600 units a day, was given to four normal subjects and to five patients with surgically induced hypoparathyroidism. Initially, parathyroid extract decreased urinary magnesium for 1-3 days (mean, 1.4 days) and urinary calcium for 1-4 days (mean, 2.6 days) in the patients with hypoparathyroidism only. Continued treatment with parathyroid extract in two of the normal subjects and four of the patients for a total of 10 days increased urinary calcium and magnesium to values which exceeded control values without lowering serum values, but only in the case of calcium did they exceed the normal range of serum and urinary values. The results suggest that parathyroid extract can increase the tubular reabsorption of magnesium and calcium, but its predominant effect is to increase the renal excretion of these ions, presumably by releasing them from body tissues such as bone. Whereas magnesium excretion can be altered by parathyroid extract, normal serum values in the patients with hypoparathyroidism suggest that this ion, unlike calcium, is not dependent on the parathyroid glands for its regulation.