[Effects of growth factors and estrogen on the proliferation and prolactin gene expression in anterior pituitary cells of rats].
OBJECTIVE
Detect the effects of exogenous 17 beta-estradiol (E2), epidermal growth factor (EGF), and transforming growth factor beta 1 (TGF beta 1) on the proliferation and prolactin (PRL) gene expression in primary serum-free cultured anterior pituitary cells in vitro.


METHODS
Laser scanning confocal microscopy (LSCM) and in situ hybridization in primary serum-free cultures of rat anterior pituitary cells were employed.


RESULTS
After 36 hours incubation of the monolayer with E2(10(-8) mol/L) and EGF(10(-8) mol/L), DNA and PRL mRNA contents in the cells were increased significantly (P < 0.001); and when cells were co-incubated with E2 and EGF at the same time, the levels of DNA and PRL mRNA were higher than those treated with E2 or EGF alone (P < 0.01), respectively. TGF beta 1(2 ng/ml) treatment decreased the DNA and PRL mRNA contents significantly (P < 0.001). Its inhibitory effect was reduced at the presence of E2, the DNA and PRL mRNA levels in the cells were higher than those treated with TGF beta 1 alone (P < 0.001), but still lower than E2 alone treatment (P < 0.001).


CONCLUSIONS
The results indicate that EGF and TGF beta 1 exerte stimulatory inhibitory effects, on cell proliferation and PRL gene expression in anterior pituitary cells of rats in both basal and E2-induced conditions. EGF and TGF beta 1 may be involoved in the regulation of proliferation and PRL gene expression in anterior pituitary cells in vivo; and also may be correlated with prolactin-secreting tumors formation induced by E2.
Wu
X
X
Department of Physiology, Institute of Basic Medical Sciences, PUMC and CAMS, Beijing 100005.
Zhang
R
R
Di
A
A
Shan
H
H
Xu
R
R
D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D004958:Estradiol / Q000494:pharmacology*; D008297:Male; D010903:Pituitary Gland, Anterior / Q000166:cytology* / Q000378:metabolism; D011388:Prolactin / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D016212:Transforming Growth Factor beta / Q000494:pharmacology*; D053773:Transforming Growth Factor beta1
D012333:RNA, Messenger; C508962:Tgfb1 protein, rat; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; D004958:Estradiol; D004815:Epidermal Growth Factor; D011388:Prolactin