The hipothalamic-pituitary axis regulation is altered in hCG over expressing male mice

BETINA GONZALEZ; NOELIA P. DI GIORGIO; LAURA D. RATNER; MATTI POUTANEN; ILPO HUHTANIEMI; RICARDO S. CALANDRA; VICTORIA A.R. LUX-LANTOS; SUSANA B. RULLI

Praga

Congreso; 12th European Congress of Endocrinology; 2010

European Society of Endocrinology

Male transgenic (TG) mice overexpressing both the hCGalpha- and hCGbeta- subunits present with elevated levels of circulating hCG, Leydig cell hyperplasia/hypertrophy, elevated androgen levels and infertility. In addition, serum FSH is significantly reduced in prepuberal and adult TG males compared with wild type (wt), and does not change after treatment with the antiandrogen flutamide. The aim of this study was to evaluate the regulation of the hypothalamic-pituitary axis in 4 week- old TG and wt males, by analyzing the effect of castration (Cx) for 2 weeks. We evaluated: a) serum FSH levels by radioimmunoassay (RIA); b) pituitary mRNA expression of FSHâ (Fshb), GnRH receptor (Gnrhr), estrogen receptor á (Esr1) and the common á-subunit (Cga) by qRT-PCR; c) the hypothalamic GnRH concentration and GnRH pulsatility ex-vivo (by RIA). FSH serum levels were: wt: 48.5±1.4, wt Cx: 77.5±2.0*, TG: 5.4±0.4*, TG Cx: 7.4±0.4* ng/ml (* p