EXPRESSION OF HORMONAL RECEPTORS AND PROLIFERATING CELLULAR NUCLEAR ANTIGEN IN PARS DISTALIS CELLS: STUDY IN RELATION TO SEX

ROSALES G,; FILIPPA VERÓNICA; MOHAMED F.

Mendoza

Congreso; XL Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2022

Sociedad de Biología de Cuyo

Gonadal steroids are involved in the regulation of cellular activity of pituitary pars distalis (PD). Several studies carried out in some mammals have indicated that this regulation vary in relation to sex. The viscacha (Lagostomus maximus maximus) is a native rodent to Argentina of seasonal reproductive patterns. From February to April, the no pregnant females experience a massive polyovulation phenomeno and they prepare for an extensive pregnancy, and the males are in their reproductive period. The aim of this work was to study and quantify the colocalization of androgen receptors (AR), estrogen receptors alpha (ER), and proliferating cellular nuclear antigen (PCNA) in LH-, FSH-, GH-, PRL- and folliculostellate (FS)-cells of pituitary PD of adult male and female viscachas. In each group, four pituitary glands were collected and processed for light microscopy. Colocalization of antigens in PD cells was detected by double-immunohistochemistry. These cells were quantified by morphometric and statistical analysis. In males and females, the location of AR was mainly observed in GH-cells (P < 0.01). In females, the ER was mainly found in the PRL-cells (P < 0.01) and were numerous in FS cells compared with males (P < 0.01). Instead, in males the ER was frequently observed in GH-cells (P < 0.01). In females numerous GH-cells and LH-cells expressed PCNA (P < 0.01). While in males the expression of PCNA was mainly in FSH-cells and LH-cells (P < 0.05). The results show that the AR are important to regulate the activity of somatotrophs in both sexes. The ER regulate the activity of lactotrophs in females probably in preparation for pregnancy. In males these receptors affect the somatotrophs who might be very active to maintain the metabolic conditions during the reproductive period. In females, cell proliferation is mainly in somatotrophs and gonadotrophs-LH probably because these cells must maintain metabolism and particularly ovary for the reproductive process. In males, cell proliferation occurs basically in gonadotrophs indicating the great activity of the gonadotrophic axis at this time of the seasonal reproductive cycle. Finally, double immunohistochemistry provided morphological evidence for the existence the specific regulation of the cellular activity in the different pituitary PD populations in relation to sex of the animals. Further studies are needed to understand the mechanisms of regulation activated by gonadal steroids in the viscacha pituitary.