Morphological relation between folliculostellate and endocrine cells in the pituitary pars distalis of viscacha.

ACOSTA, MARIANO; FILIPPA, VERÓNICA; MOHAMED, FABIAN

Ciudad de La Punta, San Luis, Argentina

Congreso; XXVII Reunión Científica Anual de la Sociedad de Biología de Cuyo; 2009

Sociedad de Biología de Cuyo, Facultad de Química, Bioquímica y Farmacia - UNSL, y Universidad de La Punta.

The folliculostellate cells (FSC) have been reported in pituitary pars distalis (PD) of several mammalian species. The purpose of this work was to study the relation between the FSC and endocrine cells of the pituitary PD of adult male viscacha. Doubleinmmunostaining were performed and the antibodies against S-100 protein, Prl, LH, FSH, ACTH, GH and TSH were used. DAB and New Fuchsin were selected as chromogens. The FSC (S-100-ir) originated follicles and were disposed in groups or isolated. They were stellate-like in shape and exhibited short cytoplasmic processes that contacted with blood vessels and endocrine cells. The hormone secreting cells of PD, mainly lactotrophs (Prl-ir), gonadotrophs (LH-ir and FSH-ir) and corticotrophs (ACTH-ir) were found to be close associated with FSC and follicles, while somatotrophs (GH-ir), although widely distributed in the PD parenchyma, were observed in proximity to the follicular structures. On the other hand, thyrotrophs (TSH-ir), which were mainly distributed in the medial and cephalic regions, were not found close to the follicles. The follicular colloid was immunostained with anti-S-100 and occasionally with anti-Prl and anti-LH. This differential association of FSC with endocrine cells suggests a dynamic communication and a probable paracrine regulation between them in pituitary PD of viscacha.