NOVEL EXPRESSION OF LOCAL GnRH AT SPECIFIC STAGES OF MAMMARY GLAND DEVELOPMENT OF VIZCACHAS SUGGESTS A MODULATORY ROLE IN TISSUE REMODELING (Rodentia: Chinchillidae).

CORSO MC, PROIETTO S, CORTASA S, SCHMIDT AR, INSERRA PIF, DI GIORGIO NP, LUX-LANTOS V, DORFMAN VB, VITULLO AD, HALPERIN J

Mar del Plata

Congreso; LXIII Reunión Científica Anual de la Sociedad Argentina de Investigaciones Clínicas; 2018

Sociedad Argentina de Investigaciones Clínicas

Mammary glands (MG) exhibit extensive tissue remodeling during pregnancy and lactation. Although progesterone, estradiol and prolactin (PRL) are the main regulators of MG development, there are several other factors that also intervene in the dynamics of this gland. The expression of gonadotropin-releasing hormone (GnRH) has been previously reported in reproductive extra-hypothalamic tissues (ovaries, placenta, endometrium, oviducts and in mast cells located in the MG) where it would act by autocrine or paracrine manner. In addition, a GnRH-PRL dependent regulation has been described in both hypothalamus and MG. Herein, we measured GnRH in mammary tissue by RIA and examined the expression of both GnRH and its receptor (GnRHR) by PCR , immunohistochemistry (IHQ) and immunofluorescence (IF) in MG of vizcachas at early-, mid-, term-pregnancy and during lactation. We also examined the expression of Egr-1 as a biomarker of GnRH active signaling. We related these data with the expression of PRL and its receptor (PRLR). Although mammary GnRH content at mid-pregnancy was minimum, MG exhibited the maximum levels of GnRHR and Egr-1 suggesting an active GnRH signaling. On the contrary, MG of lactating females exhibited the highest levels of local GnRH (p