Evidence for extrathyroidal formation of 3-iodothyronamine in humans as provided by a novel monoclonal antibody-based chemiluminescent serum immunoassay.
J Clin Endocrinol Metab
; 96(6): 1864-72, 2011 Jun.
Article
em En
| MEDLINE
| ID: mdl-21490071
ABSTRACT
CONTEXT Thyronamines are thyronergic metabolites of thyroid hormones. Lack of reliable and sensitive detection methods for endogenous 3-iodothyronamine (3-T(1)AM) has so far hampered progress in understanding their physiological action and role in endocrine homeostasis or pathophysiology of diseases. OBJECTIVE:
We characterized newly generated mouse monoclonal 3-T(1)AM antibodies and established a monoclonal antibody-based chemiluminescence immunoassay as a powerful tool for monitoring 3-T(1)AM levels in investigations addressing altered serum profiles and potential sites of origin and action of 3-T(1)AM in humans. DESIGN ANDSETTING:
Our exploratory study on 3-T(1)AM serum levels in humans measured 3-T(1)AM concentrations in comparison with thyroid hormones. PATIENTS OR OTHERPARTICIPANTS:
Thirteen adult healthy subjects, 10 patients with pituitary insufficiency, and 105 thyroid cancer patients participated.INTERVENTIONS:
INTERVENTIONS included l-T(4) withdrawal in patients with pituitary insufficiency as well as TSH-suppressive T(4) substitution in thyroid cancer patients.RESULTS:
3-T(1)AM was reliably quantified in human serum and stable after storage at room temperature and 4 C overnight as well as after four freeze-thaw cycles. The median serum concentration in healthy subjects was 66 ± 26 nm. 3-T(1)AM was also detected in T(4)-substituted thyroid cancer patients. Although free T(4) and T(3) significantly decreased during T(4) withdrawal, 3-T(1)AM levels remained constant for 6 d.CONCLUSION:
Because higher 3-T(1)AM levels are detectable in T(4)-substituted thyroid cancer patients after thyroidectomy/radioiodine treatment compared with healthy controls, we concluded that 3-T(1)AM is mainly produced by extrathyroidal tissues. The serum profile during T(4) withdrawal suggests either a long half-life or persisting 3-T(1)AM release into serum from intracellular thyroid hormone precursors or stores.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Tironinas
/
Neoplasias da Glândula Tireoide
/
Hipopituitarismo
Limite:
Adolescent
/
Adult
/
Aged
/
Aged80
/
Female
/
Humans
/
Male
/
Middle aged
Idioma:
En
Revista:
J Clin Endocrinol Metab
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
Alemanha