Experimental investigations on immunology of the parathyroid gland.

Repeated inoculation of homologous parathyroid tissue in dogs induced isoimmune hypoparathyroidism, with all the characteristic biochemical and histopathological features and the presence of complement fixing antibodies in the serum. Disturbances of calcium and phosphorus metabolism were similar to, but less severe than, those observed in dogs with hypoparathyroidism induced by complete thyro-parathyroidectomy. Injection of rabbits with crude extracts of dog, rat, hog and human parathyroid or with bovine parathormone (PTH), each incorporated in Freund's adjuvant, resulted in the development of complement fixing and precipitating antibodies: these reacted with the corresponding tissue preparations, but did not show cross-reactivity. Antibodies were not detected in the serum of normal dogs or in control dogs inoculated with Freund's adjuvant alone. Study of the parathyroid glands by electron microscopy provided information on the mechanism of PTH secretion and synthesis in normal dogs and in those with hypoparathyroidism.