17-beta estradiol acts as a negative modulator of the insulin-induced lactotroph cell proliferation through the estrogen receptor alpha via nitric oxide/ guanylyl cyclase/ cGMP

GUTIéRREZ SILVINA; PETITI JUAN PABLO; SOSA LILIANA; FOZATTI LAURA; DEPAUL ANA LUCíA; MASINI - REPISO AM; TORRES ALICIA I

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Oxford; Año: 2010 vol. 43 p. 505 - 505

h4>OBJECTIVES: 17â-oestradiol interacts with growth factors to modulate lactotroph cell population. However, contribution of isoforms of the oestrogen receptor in these activities is not fully understood. In the present study, we have established participation of á and â oestrogen receptors in effects of 17â-oestradiol on lactotroph proliferation induced by insulin and shown involvement of the NO/sGC/cGMP pathway. MATERIALS AND METHODS: Cell cultures were prepared from anterior pituitaries of female rats to evaluate lactotroph cell proliferation using bromodeoxyuridine (BrdUrd) detection, protein expression by western blotting and cGMP by enzyme immunoassay. RESULTS: In serum-free conditions, 17â-oestradiol and á and â oestrogen receptor agonists (PPT and DPN) failed to increase numbers of lactotroph cells undergoing mitosis. Co-incubation of 17â-oestradiol/insulin and PPT/insulin significantly decreased lactotroph mitogenic activity pro