Skip to main content
NCBI home page
The Journal of Clinical Investigation logoLink to The Journal of Clinical Investigation
. 1975 Jun;55(6):1245–1253. doi: 10.1172/JCI108043

Metabolism of bovine parathyroid hormone. Immunological and biological characteristics of fragments generated by liver perfusion.

J M Canterbury, L A Bricker, G S Levey, P L Kozlovskis, E Ruiz, J E Zull, E Reiss
PMCID: PMC301879  PMID: 166093

Abstract

The metabolism of bovine parathyroid hormone (PTH) by the perfused rat liver was studied. Labeled hormone, with or without cold hormone, was infused into the circulating perfusion medium containing various calcium concentrations. Pefusate samples at various time periods after the introduction of PTH into the system were chromatographed on Bio-gel P-10; radioactivity and/or immunoreactivity were measured in eluted fractions. Before the perfusion, all immuno- and radioactivity eluted in a single peak, with an apparent mol wt of 9,500 (peak I). After perfusion for 15 min, two other peaks with approximate mol wt of 7,000 (peak II) and 3,500 (peak III) were discernible. Peak I contained both NH2-terminal and COOH-terminal immunoreactivity and was biologically active at all time periods tested. The relative contribution of NH2-terminal and COOH-terminal immunoreactivity to the total immunoreactivity remained constant in this peak throughout the perfusion. In every respect, peak I had the characteristics of intact hormone. At all times, peak II consisted of only COOH-terminal immunoreactivity and was biologically inactive. At early time periods, peak III contained predominantly NH2-terminal immunoreactivity and was biologically active. With time, the relative contribution of NH2-terminal immunoreactivity decreased strikingly while that of COOH-terminal immunoreactivity increased. The three peaks identified in these experiments were analogous in size, biological activity, and immunological characteristics to those we have previously described for fractionated human hyperparathyroid serum. The rate of metabolism of PTH appeared to be regulated by the calcium concentration in the medium. At a high concentration of calcium (greater than 11 mg/100 ml), PTH metabolism was greatly retarded. At a low concentration of calcium (smaller than 5 mg/100 ml), the rate of metabolism was greatly increased. The physiological significance of our observations on the metabolism of PTH by isolated perfused rat liver is not known. However, since such metabolism results in a biologically active fragment, it is suggested that metabolism of intact hormone may be required before full biological expression is possible.

Full text

PDF
1245

Selected References

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

  1. Arnaud C. D., Goldsmith R. S., Bordier P. J., Sizemore G. W. Influence of immunoheterogeneity of circulating parathyroid hormone on results of radioimmunoassays of serum in man. Am J Med. 1974 Jun;56(6):785–793. doi: 10.1016/0002-9343(74)90806-7. [DOI] [PubMed] [Google Scholar]
  2. Arnaud C. D., Tsao H. S., Littledike T. Radioimmunoassay of human parathyroid hormone in serum. J Clin Invest. 1971 Jan;50(1):21–34. doi: 10.1172/JCI106476. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Berson S. A., Yalow R. S. Immunochemical heterogeneity of parathyroid hormone in plasma. J Clin Endocrinol Metab. 1968 Jul;28(7):1037–1047. doi: 10.1210/jcem-28-7-1037. [DOI] [PubMed] [Google Scholar]
  4. Brewer H. B., Jr, Fairwell T., Ronan R., Sizemore G. W., Arnaud C. D. Human parathyroid hormone: amino-acid sequence of the amino-terminal residues 1-34. Proc Natl Acad Sci U S A. 1972 Dec;69(12):3585–3588. doi: 10.1073/pnas.69.12.3585. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Brewer H. B., Jr, Ronan R. Bovine parathyroid hormone: amino acid sequence. Proc Natl Acad Sci U S A. 1970 Dec;67(4):1862–1869. doi: 10.1073/pnas.67.4.1862. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Bricker L. A., Kozlovskis P. L., Goodman M. G. Negative feedback in sterol biosynthesis and lipoprotein release by the perfused rat liver. Proc Soc Exp Biol Med. 1973 Jun;143(2):375–378. doi: 10.3181/00379727-143-37324. [DOI] [PubMed] [Google Scholar]
  7. Canterbury J. M., Levey G. S., Reiss E. Activation of renal cortical adenylate cyclase by circulating immunoreactive parathyroid hormone fragments. J Clin Invest. 1973 Feb;52(2):524–527. doi: 10.1172/JCI107211. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Canterbury J. M., Levy G., Ruiz E., Reiss E. Parathyroid hormone activation of adenylate cyclase in liver. Proc Soc Exp Biol Med. 1974 Nov;147(2):366–370. doi: 10.3181/00379727-147-38343. [DOI] [PubMed] [Google Scholar]
  9. Canterbury J. M., Reiss E. Multiple immunoreactive molecular forms of parathyroid hormone in human serum. 1. Proc Soc Exp Biol Med. 1972 Sep;140(4):1393–1398. doi: 10.3181/00379727-140-36681. [DOI] [PubMed] [Google Scholar]
  10. DAVIS R., TALMAGE R. V. Evidence for liver inactivation of parathyroid hormone. Endocrinology. 1960 Feb;66:312–314. doi: 10.1210/endo-66-2-312. [DOI] [PubMed] [Google Scholar]
  11. Exton J. H., Park C. R. Control of gluconeogenesis in liver. I. General features of gluconeogenesis in the perfused livers of rats. J Biol Chem. 1967 Jun 10;242(11):2622–2636. [PubMed] [Google Scholar]
  12. 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. Endocrinology. 1972 May;90(5):1177–1184. doi: 10.1210/endo-90-5-1177. [DOI] [PubMed] [Google Scholar]
  13. Fischer J. A., Oldham S. B., Sizemore G. W., Arnaud C. D. Calcium-regulated parathyroid hormone peptidase. Proc Natl Acad Sci U S A. 1972 Aug;69(8):2341–2345. doi: 10.1073/pnas.69.8.2341. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Fujita T., Ohata M., Orimo H., Yoshikawa M., Maruyama M. Enzymatic hydrolysis of 125I-labeled parathyroid hormone. Endocrinol Jpn. 1969 Jun;16(3):383–389. doi: 10.1507/endocrj1954.16.383. [DOI] [PubMed] [Google Scholar]
  15. Fujita T., Orimo H., Ohata M., Yoshikawa M. Enzymatic inactivation of parathyroid hormone by rat kidney homogenate. Endocrinology. 1970 Jan;86(1):42–49. doi: 10.1210/endo-86-1-42. [DOI] [PubMed] [Google Scholar]
  16. 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]
  17. Habener J. F., Powell D., Murray T. M., Mayer G. P., Potts J. T., Jr Parathyroid hormone: secretion and metabolism in vivo. Proc Natl Acad Sci U S A. 1971 Dec;68(12):2986–2991. doi: 10.1073/pnas.68.12.2986. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Keutmann H. T., Dawson B. F., Aurbach G. D., Potts J. T., Jr A biologically active amino-terminal fragment of bovine parathyroid hormone prepared by dilute acid hydrolysis. Biochemistry. 1972 May 9;11(10):1973–1979. doi: 10.1021/bi00760a037. [DOI] [PubMed] [Google Scholar]
  19. Krishna G., Weiss B., Brodie B. B. A simple, sensitive method for the assay of adenyl cyclase. J Pharmacol Exp Ther. 1968 Oct;163(2):379–385. [PubMed] [Google Scholar]
  20. 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]
  21. Levey G. S., Epstein S. E. Myocardial adenyl cyclase: activation by thyroid hormones and evidence for two adenyl cyclase systems. J Clin Invest. 1969 Sep;48(9):1663–1669. doi: 10.1172/JCI106131. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Martin T. J., Melick R. A., de Luise M. Metabolism of parathyroid hormone. Degradation of 125I-labelled hormone by a kidney enzyme. Biochem J. 1969 Feb;111(4):509–514. doi: 10.1042/bj1110509. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Melick R. A., Martin T. J. Parathyroid hormone metabolism in man: effect of nephrectomy. Clin Sci. 1969 Dec;37(3):667–674. [PubMed] [Google Scholar]
  24. Niall H. D., Keutmann H., Sauer R., Hogan M., Dawson B., Aurbach G., Potts J., Jr The amino acid sequence of bovine parathyroid hormone I. Hoppe Seylers Z Physiol Chem. 1970 Dec;351(12):1586–1588. [PubMed] [Google Scholar]
  25. Niall H. D., Sauer R. T., Jacobs J. W., Keutmann H. T., Segre G. V., O'Riordan J. L., Aurbach G. D., Potts J. T., Jr The amino-acid sequence of the amino-terminal 37 residues of human parathyroid hormone. Proc Natl Acad Sci U S A. 1974 Feb;71(2):384–388. doi: 10.1073/pnas.71.2.384. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Reis E., Canterbury J. M. A radioimmunoassay for parathyroid hormone in man. Proc Soc Exp Biol Med. 1968 Jun;128(2):501–504. doi: 10.3181/00379727-128-33050. [DOI] [PubMed] [Google Scholar]
  27. Segre G. V., Habener J. F., Powell D., Tregear G. W., Potts J. T. Parathyroid Hormone in Human Plasma: IMMUNOCHEMICAL CHARACTERIZATION AND BIOLOGICAL IMPLICATIONS. J Clin Invest. 1972 Dec;51(12):3163–3172. doi: 10.1172/JCI107143. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Segre G. V., Niall H. D., Habener J. F., Potts J. T., Jr Metabolism of parathyroid hormone: physiologic and clinical significance. Am J Med. 1974 Jun;56(6):774–784. doi: 10.1016/0002-9343(74)90805-5. [DOI] [PubMed] [Google Scholar]
  29. Silverman R., Yalow R. S. Heterogeneity of parathyroid hormone. Clinical and physiologic implications. J Clin Invest. 1973 Aug;52(8):1958–1971. doi: 10.1172/JCI107380. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Woodhead J. S., O'Riordan J. L., Keutmann H. T., Stoltz M. L., Dawson B. F., Niall H. D., Robinson C. J., Potts J. T., Jr Isolation and chemical properties of porcine parathyroid hormone. Biochemistry. 1971 Jul 6;10(14):2787–2792. doi: 10.1021/bi00790a021. [DOI] [PubMed] [Google Scholar]
  31. Zull J. E., Repke D. W. Studies with tritiated polypeptide hormones. I. The preparation and properties of an active, highly tritiated derivative of parathyroid hormone: acetamidino-parathyroid hormone. J Biol Chem. 1972 Apr 10;247(7):2183–2188. [PubMed] [Google Scholar]

Articles from Journal of Clinical Investigation are provided here courtesy of American Society for Clinical Investigation

RESOURCES