Direct Humoral Control of Parathyroid Function in the Dog.

Abstract

Direct humoral control of parathyroid function has been demonstrated in dogs in which the isolated thyroid-parathyroid glands were perfused with high Ca or low Ca blood. The latter appears to stimulate release of parathyroid hormone or a substance with similar action. The resulting rise in systemic blood Ca does not depend on a fall in inorganic blood phosphate. The experiments demonstrate a "feedback" mechanism involving the parathyroids which is sufficiently sensitive and fast-acting to account for the acute hemeostatic control of blood Ca.