AN IMPROVED ASSAY FOR PARATHYROID HORMONE, OBSERVING THE RISE OF SERUM CALCIUM IN THYROPARATHYROIDECTOMIZED RATS

Abstract

SUMMARY Previous methods of assay of parathyroid hormone have been reviewed and none has been found to be entirely satisfactory. A new assay has been evolved in which the ability of the test substance to raise the serum calcium in rats has been measured as before, but in which combined removal of the thyroid and parathyroid glands, by blunt dissection, has been used. The range of the new assay is 2–65 U.S.P. units. The additional removal of the thyroid gland led to a considerable reduction in the scatter of the results and the new assay method is statistically acceptable.