G D Aurbach

Aqueous polyethylene glycol causes precipitation of antibody-bound peptide hormones labeled with radioactive iodine with little or no precipitation of free hormones. Based on this finding, a method of separation has been developed and applied to radioimmunoassays of insulin, parathyroid hormone, growth hormone and arginine vasopressin. The new method provides several advantages over the double-antibody precipitation method. It appears particularly valuable in immunoassays of substances of low molecular weight.

Measurement by radioimmunoassay of secretory rates for parathyroid hormone in the cow shows that hypocalcemia is the major stimulus for hormone production; hypercalcemia quickly abolishes secretion. Phosphate causes no direct effect on secretion of the hormone. Analyses for parathyroid hormone and calcium in peripheral plasma showed a simple linear inverse function of hormone concentration vs. plasma calcium in the range of 4 to 12 mg/100 ml. This led to the conclusion that calcium regulates hormonal secretion predominantly through a proportional control mechanism. The half-life of parathyroid hormone in the circulation was found to be approximately 20 min. The speed with which secretion responds to changes in blood calcium and the short half-life of hormone in plasma are consistent with recent studies showing that parathyroid hormone effects rapid changes in blood calcium. These findings emphasize the importance of the hormone in the minute to minute regulation of blood calcium. (Endocrinology83: 1043, 1968)

Journal Article Production of Parathyroid Hormone by Nonparathyroid Tumors Get access LOUIS M. SHERWOOD, LOUIS M. SHERWOOD Search for other works by this author on: Oxford Academic Google Scholar JEFFREY L. O'RIORDAN, JEFFREY L. O'RIORDAN Search for other works by this author on: Oxford Academic Google Scholar G. D. AURBACH, G. D. AURBACH Search for other works by this author on: Oxford Academic Google Scholar JOHN T. POTTS, JR. JOHN T. POTTS, JR. Search for other works by this author on: Oxford Academic Google Scholar The Journal of Clinical Endocrinology & Metabolism, Volume 27, Issue 1, 1 January 1967, Pages 140–146, https://doi.org/10.1210/jcem-27-1-140 Published: 01 January 1967 Article history Received: 17 August 1966 Accepted: 30 October 1966 Published: 01 January 1967

A method is described for the preparation of isolated bovine parathyroid cells. Fresh, minced bovine parathyroid tissue is incubated with 2 mg/ml collagenase and 50 mug/ml DNAse for 1 h at 37 C with periodic pipetting. Parthyroid cells are separated from contaminating fat cells and red cells by low speed centrifugation. The resulting cell preparation is indistinguishable from parathyroid cells in intact bovine glands by light and electron microscopy. Hormone release is linear for at least 3 h at both high (2.0 mM) and low (0.5 mM) calcium concentrations and is inversely proportional to divalent cation concentration between 0.3 mM and 1.0 mM calcium as been observed previously both in vivo and in vitro. As in previous studies, hormone release is also stimulated up to 2-fold by 10(6) M (-)isoproterenol, an effect blocked by 10(-6)M (-)propranolol, suggesting a beta-adrenergic effect. Such a cell preparation should be useful for studying hormone binding and effects on cyclic nudleotides and cellular transport phenomena in both normal amd abnormal tissue.