Detection in human serum by radioimmunoassay of histidyl-proline diketopiperazine, a metabolite of thyrotropin-releasing hormone.

Journal Article (Journal Article)

Cyclo(His-Pro) is believed to be a metabolite of TRH. A specific antiserum directed against cyclo(His-Pro) was used to detect immunoreactive material in human serum. Gel filtration column chromatography was used to establish that cyclo(His-Pro)-like immunoreactivity was found not only in free form established to be identical to cyclo(His-Pro) by high pressure liquid chromatography analysis on reverse phase and cation exchange columns, but also in a fraction of about 100,000 mol wt. Free cyclo(His-Pro) was released by heating column fractions of 70,000 mol wt that were not immunoreactive before heating. A procedure for estimation of the content of free cyclo(His-Pro) in human serum was developed. Normal levels of cyclo(His-Pro) determined by this procedure were in the range of 11-33 pmol/ml. The level of cyclo(His-Pro) in sera of individuals with hypothyroidism, hyperthyroidism, or alcoholic cirrhosis was in the normal range, while patients with renal failure had approximately 3-fold elevated levels of the peptide. Analysis of human sera drawn at 3-h intervals over a 24-h period suggested a circadian rhythm of cyclo(His-Pro) levels.

Full Text

Duke Authors

Cited Authors

  • Takahara, Y; Battaini, F; Ross, DD; Akman, SA; Bachur, NR; Bailey, KR; Lakatos, E; Peterkofsky, A

Published Date

  • February 1, 1983

Published In

Volume / Issue

  • 56 / 2

Start / End Page

  • 312 - 319

PubMed ID

  • 6401750

International Standard Serial Number (ISSN)

  • 0021-972X

Digital Object Identifier (DOI)

  • 10.1210/jcem-56-2-312


  • eng

Conference Location

  • United States