GONADOTROPIN-RELEASING HORMONE, GLUTAMATE AND ESTRADIOL INTERACTION IN THE MODULATION OF THE REPRODUCTIVE CYCLE OF THE SOUTH AMERICAN PAINS VIZCACHA (LAGOSTOMUS MAXIMUS).

PABLO IGNACIO FELIPE INSERRA , SANTIAGO ELÍAS CHARIF , VICTORIA FIDEL , ALEJANDRO RAÚL SCHMIDT , SANTIAGO ANDRÉS CORTASA , SOFIA PROIETTO , MARÍA CLARA CORSO ; NOELIA PAULA DI GIORGIO , VICTORIA LUX-LANTOS; HALPERIN J; ALFREDO VITULLO , VERÓNICA BERTA DORFMAN

Mar del Plata

Congreso; LXIII Reunión Científica Anual de la Sociedad Argentina de Investigación Clínica.; 2018

Sociedad Argentina de Investigación Clínica

Lagostomus maximus shows peculiar reproductive features such as massivepoliovulation and reactivation of the hypothalamic-pituitary-ovarian (HPO) axis duringpregnancy with follicular recruitment and ovulation at mid-gestation. Its gonadotropinreleasing hormone (GnRH) neurons at preoptic (POA) and supraoptic (SON) areasexpress estrogen receptor alpha (ERalpha). Glutamate (GLU) modulates GnRH neuronsthrough its specific receptor NMDA-R in an estradiol (E2) dependent manner. The aimof this work was to study the involvement of E2 on the glutamatergic system and itsmodulation on GnRH expression. Their involvement on HPO axis activation duringgestation was evaluated. Adult vizcachas were used under three experimentalconditions: 1) non-pregnant (NP), 2) early-pregnant (EP), mid-pregnant (MP), andterm-pregnant (TP) females, and 3) NP ovariectomized (OVX) females injected with E2(1mg/kg/day) during 5 days (OVX+E2). SHAM animals were used as controls. N=6 pergroup. E2 serum levels, and hypothalamic GnRH and NMDA-R were studied by ELISA,RIA, Western-blot, and immunofluorescence. MP females showed higher serum E2levels, and GnRH and NMDA-R expression vs. EP & TP. Hypothalamic explants of NPincubated with GLU +/- GLU receptors antagonist showed significant GnRH deliveryincrements when NMDA-R was blocked (p