info:eu-repo/semantics/article
Upregulation of Angiotensin II type 2-receptor expression in estrogen-induced pituitary hyperplasia
Fecha
2004-01Registro en:
Suárez, Cecilia Ana; Diaz, Graciela Susana; Gonzalez Iglesias, A.; Cristina, Silvia Carolina; Becu, Damasia; Upregulation of Angiotensin II type 2-receptor expression in estrogen-induced pituitary hyperplasia; American Physiological Society; American Journal Of Physiology-endocrinology And Metabolism; 286; 5; 1-2004; E786-E794
0193-1849
1522-1555
CONICET Digital
CONICET
Autor
Suárez, Cecilia Ana
Diaz, Graciela Susana
Gonzalez Iglesias, A.
Cristina, Silvia Carolina
Becu, Damasia
Resumen
Recent evidence shows that reexpression and upregulation of angiotensin II (ANG II) type 2 (AT2) receptor in adult tissues occur during pathological conditions such as tissue hyperplasia, inflammation, and remodeling. In particular, expression of functional AT2 receptors in the pituitary and their physiological significance and regulation have not been described. In this study, we demonstrate that chronic in vivo estrogen treatment, which induces pituitary hyperplasia, enhances local AT2 expression (measured by Western blot and RT-PCR) concomitantly with downregulation of ANG II type 1 (AT1) receptors. In vivo progesterone treatment of estrogen-induced pituitary hyperplasia did not modify either the ANG II receptor subtype expression pattern or octapeptide-induced and AT1-mediated calcium signaling. Nevertheless, an unexpected potentiation of the ANG II prolactin-releasing effect was observed in this group, and this response was sensitive to both AT1 and AT2 receptor antagonists. These data are the first to document that ANG II can act at the pituitary level through the AT2 receptor subtype and that estrogens display a differential regulation of AT1 and AT2 receptors at this level.