Dopamine induces apoptosis of anterior pituitary cells by ROS production and caspase activation

D. RADL; J. FERRARIS; G. JAITA; V. ZALDIVAR; G. EIJO; A. SEILICOVICH; D. PISERA

Rio de Janeiro

Congreso; 13º International Congress of Endocrinology; 2008

Dopamine induces apoptosis of anterior pituitary cells by ROS production and caspase activation Dopamine (DA) is a catecholamine involved in the inhibition of lactotroph proliferation and prolactin secretion. We have reported that dopamine induces apoptosis of anterior pituitary cells and lactotrophs by D2 receptor activation in an estrogen dependent manner. It has been reported that DA exerts its proapoptotic action by ROS production and caspase activation in neurons. In the present study we investigated the role of ROS and caspases in the apoptosis induced by DA on anterior pituitary cells. Primary cultures of anterior pituitary cells from ovarietomized rats were incubated with estradiol (E2, 10-9 M, 48 h). The medium was removed and the cells were incubated with E2 in the presence or absence of N-acetyl-cysteine (NAC, 5mM, 30 min) or a caspase inhibitor (ZVAD-FMK, 30 min). Then DA (10-6 M) was added for further 4 h. The number of apoptotic cells was determined by TUNEL. The presence of either NAC or ZVAD-FMK blocked the apoptosis induced by DA. These observations indicate that ROS production and caspase activation are involved in dopamine-induced apoptosis of anterior pituitary cells.