INV SUPERIOR JUBILADO
SEILICOVICH Adriana
artículos
Título:
Gonadal steroids modulate FAS-induced apoptosis of lactotropes and somatotropes
Autor/es:
G. JAITA; S. ZARATE; L. FERRARI; D. RADL; J. FERRARIS; G. EIJO; V. ZALDIVAR; D. PISERA; A. SEILICOVICH
Revista:
ENDOCRINE
Editorial:
HUMANA PRESS INC
Referencias:
Lugar: Oregon; Año: 2011 vol. 39 p. 21 - 27
ISSN:
0969-711X
Resumen:
We have previously reported that Fas activation induces apoptosis of anterior pituitary cells from rats at proestrus but not at diestrus and in an estrogen-dependent manner. In the present study, we evaluated the effect of Fas activation on apoptosis of lactotropes and somatotropes during the estrous cycle and explored the action of gonadal steroids on Fas-induced apoptosis. Also, we studied whether changes in Fas expression are involved in the apoptotic response of anterior pituitary cells. Fas activation increased the percentage of TUNEL-positive lactotropes and somatotropes at proestrus but not at diestrus. FasL triggered apoptosis of somatotropes only when cells from ovariectomized rats were cultured in the presence of 17beta-estradiol (E2). Progesterone (P4) blocked the apoptotic action of the Fas/FasL system in lactotropes and somatotropes incubated with E2. Both E2 and P4 increased the percentage of cells expressing Fas at the cell membrane . Our results show that Fas activation induces apoptosis of lactotropes and somatotropes at proestrus but not at diestrus. Gonadal steroids may be involved in the apoptotic response of lactotropes and somatotropes, suggesting that Fas activation is implicated in the renewal of these pituitary subpopulations during the estrous cycle. The effect of gonadal steroids on Fas expression may be only partially involved in regulation of the Fas/FasL apoptotic pathway in anterior pituitary gland.