Eur J Anat, 10 (3): 143-149 (2006)

Apoptosis is involved in the anti-proliferative effect of corticosteroid in non-tumoral ACTH pituitary cells

Montero M.C., Vazquez R., Rubio M., Blanco E., Riesco J.M., Herrero J.J., Vazquez G., Riesco-Lopez J.M., Gonzalez R., Carretero M., Basco M., Carretero J.

Department of Human Anatomy and Histology, Institute of Neurosciences of Castilla Y León, University of Salamanca, Spain; Departamento de Anatomía e Histología Humanas, Laboratorio de Neuroendocrinología, Facultad de Medicina, Avda. Alfonso X el Sabio, s/n, E-37007 Salamanca, Spain

ABSTRACT Glucocorticoids are the physiological negative feedback on ACTH secretion and may be involved in regulating the maintenance of the population of hypophyseal ACTH-cells, because following surgical ablation, adrenalectomy induces an increase in the number of these cells in the early stages. Glucocorticoids have been implicated in the induction of apoptosis in several tissues; but they have been little considered as hormonal inducers of apoptosis in the pituitary gland. By means of a double immunohistochemical study for PCNA and ACTH and a double assay by ISEL and immunohistochemistry for ACTH, the aim of the present study was to analyse whether corticosterone induces apoptosis and inhibits cellular proliferation to control non-tumoral ACTH-cells in the pituitary gland. For this purpose untreated, sham-operated and adrenalectomized rats, treated or not with corticosterone, were compared. The results of the present study demonstrate a very important decrease in proliferation and an increase in apoptosis of pituitary ACTH-positive cells induced by corticosterone, suggesting that the number of pituitary ACTH-producing cells is mainly controlled by glucocorticoids by means of cellular proliferation and apoptosis.

Keywords: corticosterone, corticotropin, adrenalectomy, animal experiment, animal model, animal tissue, apoptosis, article, cell proliferation, controlled study, corticotropin release, drug effect, drug inhibition, electrosurgery, hypophysis cell, immunohistochemistry, negative feedback, nonhuman, rat