[The effects of gastrin-releasing peptide (GRP) and vasoactive intestinal polypeptide (VIP) on the prolactin (PRL) gene transcription of pitutitary PRL releasing tumor of rat].
The effects of gastrin-releasing peptide (GRP) and vasoactive intestinal polypeptide (VIP) on the prolactin gene transcription of cultured pituitary of male Sprague-Dawley (SD) rats PRL releasing tumor (PPRT) (induced by estradiol) cells were studied. The PRL mRNA levels were determined by in situ hybridization of cytoplasmic RNA with a DIG-labeled PRL cDNA probe. PRL mRNA levels didn't change when the PPRT cells were incubated with 10(-8) mol/L or 10(-7) mol/L GRP for 24 h, but decreased by 20% when GRP was increased to 10(-6) mol/L (P < 0.05). The PRL mRNA level increased to 1.60, 2.10, 2.21 times of the control group when the PPRT cells were respectively incubated with 10(-8), 10(-7), 10(-6) mol/L VIP for 24 h (P < 0.05). The PRL mRNA level didn't change when the PPRT tumor cells were incubated with 10(-8) mol/L E2 for 48 h, but did increase to 2.80 and 2.92 times of the control group respectively when 10(-7) mol/L and 10(-6) mol/L E2 were used. The results above indicated that GRP and VIP exert an inhibitory and a stimulatory effect on RPL gene transcription respectively, while the stimulatory action of E2 on PRL secretion is a direct one.
Di
A K
AK
Department of Physiology, Institute of Basic Medical Sciences, CAMS and PUMC, Beijing.
Shan
H M
HM
Huang
M Y
MY
Xu
R K
RK
D000818:Animals; D004958:Estradiol; D019886:Gastrin-Releasing Peptide / Q000494:pharmacology*; D008297:Male; D010911:Pituitary Neoplasms / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology*; D011388:Prolactin / Q000096:biosynthesis / Q000235:genetics*; D015175:Prolactinoma / Q000139:chemically induced / Q000473:pathology*; D012333:RNA, Messenger / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D014158:Transcription, Genetic; D014407:Tumor Cells, Cultured; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D012333:RNA, Messenger; D014660:Vasoactive Intestinal Peptide; D004958:Estradiol; D019886:Gastrin-Releasing Peptide; D011388:Prolactin