help button home button Endocrine Society JCEM
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
This Article
Right arrow Full Text (PDF)
Right arrow Submit a related Letter to the Editor
Right arrow Purchase Article
Right arrow View Shopping Cart
Right arrow Alert me when this article is cited
Right arrow Alert me when eLetters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow Request Copyright Permission
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Phlipponneau, M.
Right arrow Articles by Bertagna, X.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Phlipponneau, M.
Right arrow Articles by Bertagna, X.

Journal of Clinical Endocrinology & Metabolism, Vol 76, 325-329, Copyright © 1993 by Endocrine Society

ARTICLES

Plasma immunoreactive joining peptide in man: a new marker of proopiomelanocortin processing and corticotroph function

M Phlipponneau, F Lenne, MF Proeschel, F Girard, JP Luton and X Bertagna
Centre de Recherche sur les Maladies Endocriniennes et Metaboliques, Hopital Cochin, Paris, France.

Joining Peptide (JP) is a 30 amino acid fragment separating the N- terminal peptide and ACTH within their common polypeptide precursor POMC. Using antibody Jamie directed against the C-terminal amidated residue Glu-NH2 we studied the molecular weight forms and the variations of plasma immunoreactive (IR)-JP in man under various physiological, pharmacological, and pathological conditions. In 21 plasma samples from patients with ACTH hypersecretory syndromes from pituitary and nonpituitary tumors, IR-JP had the same elution pattern on Sephadex G-75 showing a predominant, if not single, peak corresponding to a mol wt of 7000 as expected for a JP-homodimer. Normal male volunteers at 0800 h had plasma IR-JP values ranging from undetectable (< 6 pmol/L) to 28 pmol/L; all values were suppressed by the overnight 1 mg dexamethasone test. Plasma IR-JP had circadian variations and responded to the metyrapone test in a manner strictly similar to that of ACTH and lipotropins (LPHs). One hundred and fifteen plasma samples covering a large range of pathological ACTH values (from 10(0) to 10(4) pmol/L) were also assayed by the JP and LPH RIAs. All three immunoreactivities strongly correlated with each other with a molar ratio close to 1:1. Discrepancies were observed in two situations where both IR-JP and IR-LPH were much higher than ACTH: they occurred in some patients with the ectopic ACTH syndrome and in all patients with chronic renal failure; they are explained by the further degradation of ACTH into corticotropin-like intermediary lobe peptide in the first case, by the prolonged plasma half-life of JP and LPH, compared to that of ACTH, in the second case. These data show that JP is a normal end-product of POMC processing in man which circulates in blood mainly as a homodimer. It provides yet another marker of the overall corticotroph function and may be used to unravel abnormal POMC processing in some nonpituitary tumors.


This article has been cited by other articles:


Home page
 J. Clin. Endocrinol. Metab.Home page
N. Santoro, E. M. del Giudice, G. Cirillo, P. Raimondo, I. Corsi, A. Amato, A. Grandone, and L. Perrone
An Insertional Polymorphism of the Proopiomelanocortin Gene Is Associated with Fasting Insulin Levels in Childhood Obesity
J. Clin. Endocrinol. Metab., October 1, 2004; 89(10): 4846 - 4849.
[Abstract] [Full Text] [PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Endocrinology Endocrine Reviews J. Clin. End. & Metab.
Molecular Endocrinology Recent Prog. Horm. Res. All Endocrine Journals
Copyright © 1993 by The Endocrine Society