INVESTIGADORES
PELLIZAS Claudia Gabriela
artículos
Título:
Growth hormone treatment reduces peripheral thyroid hormone action in girls with Turner Syndrome
Autor/es:
SUSPERREGUY S; MIRAS MB; MONTESINOS MM; MASCANFRONI ID; MUÑOZ L; SOBRERO G; SILVANO L; MASINI-REPISO AM; TARGOVNIK HM; PELLIZAS CG
Revista:
CLINICAL ENDOCRINOLOGY
Editorial:
Society for Endocrinology
Referencias:
Año: 2007 vol. 67 p. 629 - 636
ISSN:
0300-0664
Resumen:
O b j e c t i v e Turner syndrome (TS) is an indication for GH therapy
in spite of the modest growth response. Somatic growth depends not
only on GH insulin-like growth factor I (IGF-I) axis but also on thyroid
hormone (TH) status. We have previously reported that supraphysiological IGF-I levels diminished TH actions in rat tissues by reducing
the nuclear TH receptor (TR). GH treatment to TS patients induces
high IGF-I levels and therefore a reduction of TH action in tissues
may be expected. We aimed at evaluating the effect of GH therapy
in TS girls on peripheral TH action.
De s i g n a n d p a t i e n t s We set up a reverse transcription-polymerase
chain reaction (RT-PCR) for TR mRNA estimation in peripheral blood
mononuclear cells (PBMC) and compared TR mRNA levels from 10
normal, 10 TS and 10 TS girls under GH therapy (0·33 mg/kg/week
for 0·52 years).
M e a s u r eme n t s After RNA extraction from PBMC, TR and β-actin
mRNAs were coamplified by RT-PCR. In addition serum biochemical
markers of TH action were measured: thyrotropin (TSH), sex
hormone binding globulin (SHBG), osteocalcin (OC), β-crosslaps
(β-CL), iodothyronines by electrochemiluminescency and IGF-I by
immunoradiometric assay (IRMA) with extraction.
R e s u l t s TR mRNAs from PBMC were reduced in TS patients under
GH treatment. In turn, serum TSH, OC, β-CL and IGF-I were
increased while SHBG was reduced by GH treatment in TS patients.
C o n c l u s i o n s GH treatment reduced TR expression in PBMC and
biochemical serum markers of TH action. These results suggest that
GH treatment in TS patients impair peripheral TH action at tissue
level and prompt a role in the reduced growth response to the therapy.