EXPERIMENTAL OBSERVATIONS ON IRRADIATED, NORMAL, AND PARTIALLY PARATHYROIDECTOMIZED RABBITS : I. THE EFFECTS OF PARTIAL PARATHYROIDECTOMY.

Previous irradiation of rabbits with ultra-violet light, with a consequent hypertrophy of the parathyroid glands, resulted in some degree of protection to these animals, when part of the parathyroid tissue was extirpated. This fact indicates that the remaining hyperplastic tissue was potentially active, and that the increased factor of safety represented by this condition of the remaining tissue resulted in less loss of blood calcium, a more rapid initiation of recovery, and an absence of the rise in the inorganic phosphorus of the blood serum which was a characteristic result of partial parathyroidectomy in normal rabbits. A fall in calcium in all the irradiated rabbits, without a corresponding rise in phosphorus, shows that the drop in calcium is the primary reaction, and a rise in phosphorus a secondary reaction following parathyroidectomy. But the relation of the rise in phosphorus to the development of tetany remains obscure.