INVESTIGADORES
SUSPERREGUY Sebastian
congresos y reuniones científicas
Título:
REDUCED PERIPHEAL THYROID HORMONE (TH) ACTION IN TURNER SYNDROME (TS) PATIENTS UNDER GROWTH HORMONE (GH) THERAPY
Autor/es:
SUSPERREGUY S; MIRAS MB; MONTESINOS M; MASCANFRONI I; MUÑOZ L; SOBRERO G; SILVANO L; PELLIZAS CG
Lugar:
Viña Del Mar. Chile.
Reunión:
Congreso; XVIII Congreso de la Sociedad Latinoamericana de Endocrinología Pediátrica (SLEP); 2006
Resumen:
Introduction and objectives: we reported that GH reduced TH action in rat tissues by lessening TH receptor (TR) expression. In TS, GH therapy improves adult height although the response is below the registered in other growth disorders. High GH doses are used in TS and supraphysiological GH serum concentrations attained. Since somatic growth depends on TH status, a lesser TH action in bone induced by high GH levels may be involved in the reduced final height of TS patients. Considering bone is not a human available tissue, we aimed at assessing the effect of GH treatment to TS patients on peripheral TH action. We measured TR mRNA levels in peripheral blood mononuclear cells (PBMC) and serum markers of TH action: thyrotropin (TSH), osteocalcin (OC), ß crosslaps (ßCL) and sex hormone binding globulin (SHBG) levels. Methodology: Ten normal, 10 TS and 10 TS under GH treatment (recombinant GH from mammalian or E. Coli cells, for at least 6 months, 0.33 mg/kg/week) were enrolled (5-14 y/o, prepuberal girls). Total RNA from PBMC (ficoll-hypaque) was extracted and TR mRNAs semi-quantified (assessed in parallel to the house-keeping ß-actin gene by RT-PCR). Serum TSH, OC, ßCL and SHBG were measured by EQLIA (Roche Elecsys 2010). Results: 1) TR mRNAs from PBMC were similar between normal and TS, but they were significantly reduced in TS-GH treated vs. TS; 2) GH therapy increased TSH, OC and ßCL, and reduced SHBG levels. Conclusions: GH reduced TRs from PBMC and some serum markers of TH action in TS patients. This effect would also take place at bone level and may be one of the factors involved in the failure to properly respond to GH.