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. 1969 Feb;111(4):509–514. doi: 10.1042/bj1110509

Metabolism of parathyroid hormone. Degradation of 125I-labelled hormone by kidney enzyme

T J Martin 1, R A Melick 1, M de Luise 1
PMCID: PMC1187571  PMID: 5774475

Abstract

A study was made of the enzymic degradation of 125I-labelled parathyroid hormone by rat kidney microsomes. Incubation with microsomes resulted in rapid destruction of the labelled hormone. The microsomal factor was not separable by dialysis, and the reaction was favoured by pH values in the physiological range. Velocity of the reaction varied directly as the substrate concentration, and additional crude parathyroid hormone (trichloroacetic acid-precipitated, 3·68mg./ml.) inhibited destruction of labelled hormone. There was much less inhibition with added trichloroacetic acid-precipitated calcitonin (3·92mg./ml.) and virtually none with added pig insulin (3·80mg./ml.). Gel filtration of control medium on P6 (Bio-Gel) yielded one radioactive peak at the void volume. After incubation with microsomes three further peaks were obtained on gel filtration. Only the void-volume peak contained intact 125I-labelled parathyroid hormone, indicating that the microsomal enzyme degraded labelled hormone to a number of smaller fragments.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. AURBACH G. D. Isolation of parathyroid hormone after extraction with phenol. J Biol Chem. 1959 Dec;234:3179–3181. [PubMed] [Google Scholar]
  2. AURBACH G. D., POTTS J. T., Jr PARTITION OF PARATHYROID HORMONE ON SEPHADEX G-100. Endocrinology. 1964 Aug;75:290–292. doi: 10.1210/endo-75-2-290. [DOI] [PubMed] [Google Scholar]
  3. Camu F., Conard V. Effet de l'ocytocine sur l'inactivation de l'insuline par le rein de rat normal in vitro. Arch Int Pharmacodyn Ther. 1966 Jul;162(1):247–252. [PubMed] [Google Scholar]
  4. HUNTER W. M., GREENWOOD F. C. Preparation of iodine-131 labelled human growth hormone of high specific activity. Nature. 1962 May 5;194:495–496. doi: 10.1038/194495a0. [DOI] [PubMed] [Google Scholar]
  5. LOWRY O. H., ROSEBROUGH N. J., FARR A. L., RANDALL R. J. Protein measurement with the Folin phenol reagent. J Biol Chem. 1951 Nov;193(1):265–275. [PubMed] [Google Scholar]
  6. MIRSKY I. A., PERISUTTI G., DIXON F. J. Destruction of I131 labeled insulin by liver slices. Proc Soc Exp Biol Med. 1954 Jun;86(2):228–230. doi: 10.3181/00379727-86-21057. [DOI] [PubMed] [Google Scholar]
  7. MIRSKY I. A., PERISUTTI G. The inactivation of insulin by liver slices of the rat. Endocrinology. 1953 Jun;52(6):698–704. doi: 10.1210/endo-52-6-698. [DOI] [PubMed] [Google Scholar]
  8. NARAHARA H. T., WILLIAMS R. H. Degradation of glucagon-I 131 by rat tissues in vitro. Endocrinology. 1957 Feb;60(2):285–289. doi: 10.1210/endo-60-2-285. [DOI] [PubMed] [Google Scholar]
  9. ORIMO H., FUJITA T., MORII H., NAKAO K. INACTIVATION IN VITRO OF PARATHYROID HORMONE ACTIVITY BY KIDNEY SLICES. Endocrinology. 1965 Feb;76:255–258. doi: 10.1210/endo-76-2-255. [DOI] [PubMed] [Google Scholar]
  10. Potts J. T., Jr, Aurbach G. D., Sherwood L. M. Parathyroid hormone: chemical properties and structural requirements for biological and immunological activity. Recent Prog Horm Res. 1966;22:101–151. doi: 10.1016/b978-1-4831-9825-5.50006-3. [DOI] [PubMed] [Google Scholar]
  11. TOMIZAWA H. H., WILLIAMS R. H. Studies on the specificity of an insulin-inactivating system of the liver. J Biol Chem. 1955 Dec;217(2):685–694. [PubMed] [Google Scholar]
  12. WILLIAMS R. H., HAY J. S., TJADEN M. B. Degradation of insulin-I 131 and glucagon-I 131 and factors influencing it. Ann N Y Acad Sci. 1959 Mar 30;74(3):513–529. doi: 10.1111/j.1749-6632.1959.tb39576.x. [DOI] [PubMed] [Google Scholar]
  13. YALOW R. S., BERSON S. A. Immunoassay of endogenous plasma insulin in man. J Clin Invest. 1960 Jul;39:1157–1175. doi: 10.1172/JCI104130. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Yalow R. S., Berson S. A. Purification of 131-I parathyroid hormone with microfine granules of precipitated silica. Nature. 1966 Oct 22;212(5060):357–358. doi: 10.1038/212357a0. [DOI] [PubMed] [Google Scholar]

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