The allografted parathyroid gland: evaluation of function in the immunosuppressed host

Parathyroid autografts were performed in 19 random bred mongrels and parathyroid allografts were exchanged between seven random bred mongrels. Three pairs of siblings from a beagle colony were immunosuppressed and parathyroid allografts exchanged between them. The parathyroid autografts were successful, while parathyroid allografts failed on all occasions in the non-immunosuppressed host. In immunosuppressed animals, however, the allografts were successful in five of six dogs. The success of parathyroid transplantation was determined by the following observations: 1) The experimental animal, having grafted parathyroid tissue as the only source of hormone, maintained a normal or near normal serum calcium concentration. 2) Following removal of the parathyroid graft, there was an immediate fall in the serum calcium concentration associated with tetany and/or death. 3) Histological study of the grafted gland revealed normal architecture, and 4) Radioimmunoassay of extracted grafts revealed moderate to large quantities of parathyroid hormone.