Abstract
A series of experiments indicated that125I-parathyroid hormone administered to the rat i.v. was deposited very rapidly in three organ systems only, bone, kidney and the liver. As indicated by increasing solubility in trichloracetic acid, the hormone seemed to be rapidly metabolized at the sites of deposition. The experiments were in part repeated employing quantitative extraction and gel filtration procedures. It was found that intact hormone predominated (82%) in the circulation but was cleared very rapidly: 91, 97, and 99% having left by 10, 30 and 60 minutes respectively after injection. The intact hormone was found at 10 minutes to be principally in kidney, bone, and liver. Although there was evidence of fragmentation preferentially to polypeptides of molecular weights of 6000, 4500 and 2500 these cannot be claimed to represent real molecular entities. By one hour, only a few per cent of the injected hormone remained intact, the bulk having been degraded to fragments of small molecular weight.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Altman, P. L., Dittmer, D. S.: Blood and other body fluids, p. 5. Washington, D. C.: Fed. Am. Soc. Exptl. Biol. 1961
DeLuca, H. F., Weller, M., Blunt, J. W., Neville, P. F.: Synthesis, biological activity and metabolism of2,23-3H vitamin D4. Arch. Biochem. Biophys.124, 122–128 (1969)
Fang, V. S., Tashjian, A. H. Jr.: Studies on the role of the liver in the metabolism of parathyroid hormone. I. Effects of partial hepatectomy and incubation of the hormone with tissue homogenates. Endocrinol.90, 1177–1184 (1972)
Izzo, M. J., Buchsbaum, D. J., Bale, W. F.: Localization of an125I-labeled rat transplantation antibody in tumors carrying the corresponding antigen. Proc. exp. Biol. Med.139, 1185–1188 (1972)
Neuman, W. F., Neuman, M. W., Lane, K., Miller, L. L., Sammon, P. J.: The metabolism of labeled parathyroid hormone. V. collected biological studies. Calcif. Tiss. Res.18, 271–287 (1975)
Neuman, W. F., Neuman, M. W., Sammon, P. J., Casarett, G. W.: The metabolism of labeled parathyroid hormone. IV. Autoradiographic studies. Calcif. Tiss. Res.18, 263–270 (1975)
Neuman, W. F., Neuman, M. W., Sammon, P. J., Lane, K.: The metabolism of labeled parathyroid hormone. II. Methodological studies. Calcif. Tiss. Res.18, 241–250 (1975)
Sammon, P. J., Brand, J. S., Neuman, W. F., Raisz, L. G.: The metabolism of labeled parathyroid hormone. I. Preparation of biologically active125I-labeled parathyroid hormone. Endocrinol.92, 1596–1603 (1973)
Skelton, H.: The storage of water by various tissues of the body. Arch. intern. Med.40, 140–152 (1972)
Yalow, R. S., Berson, S. A.: Immunoassay of plasma inulin. Methods of biochemical analysis.12, 69–96 (1964)
Zull, J. E., Repke, D. W.: The tissue localization of tritiated parathyroid hormone in thyroparathyroidectomized rats. J. biol. Chem.247, 2195–2199 (1972)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Neuman, W.F., Neuman, M.W., Sammon, P.J. et al. The metabolism of labeled parathyroid hormone. Calc. Tis Res. 18, 251–261 (1975). https://doi.org/10.1007/BF02546244
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02546244