
influence of parathyroid activity on ion
exchange in various tissues
1. balance data from three patients with hypoparathyroidism, who were
given parathyroid extract, are presented.  the metabolic response was
complex.  the data demonstrate losses of phosphate, magnesium, sodium
and potassium which were not accounted for by destruction of either bone
or non-osseous tissues.  preferential depletion of these minerals from bone,
or loss from non-osseous tissues, must be presumed.
2. the exchange of ca45, mg28, and p32 in a spectrum of rat tissues has
been studied in sham operated, parathyroidectomized, and parathyroid
extract treated rats.  the effects of parathyroidectomy on the development
of magnesium deficiency were determined.
3. four hours after parathyroidectomy, increased transport of calcium
into bone, kidney, intestine, liver, brain, and muscle was found.  six days
after parathyroidectomy equilibrium had been reestablished and exchange
rates were identical to those in sham operated animals.
4. the administration of parathyroid extract was associated with de-
creased transport of ca15, mg28, and p32 into bone.  ca15 exchange in kidney
was reduced but in all other tissues exchange of ca15 and mg28 was in-
creased.  p32 exchange in both intestine and kidney was mardedly increased
in animals receiving the extract.
5. parathyroidectomy greatly minimized the manifestations of mag-
nesium deficiency in young rats on magnesium deficient diets.
6. the results suggest that parathyroid hormone may affect the trans-
port and exchange of calcium, magnesium, and phosphate (and perhaps
sodium and potassium) in tissues other than those usually considered to
be target organs.
