Phorbol ester stimulates prolactin release but reduces prolactin mRNA in the human B-lymphoblastoid cell line IM-9-P3.
The phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) stimulated prolactin (PRL) release from the PRL producing human B-lymphoblastoid cell line IM-9-P3 within 30 min with an EC50 of 5 x 10(-9) M. Increased release was entirely attributable to a loss from intracellular PRL pools. No change in hPRL mRNA was observed during 8 h of exposure to TPA. Prolonged exposure of the cells to 2 x 10(-7) M TPA, however, led to a maximal reduction of hPRL mRNA levels after 24 h and a subsequent recovery by 72 h. Secretory rates followed a corresponding kinetic. The relative abundance of c-myc mRNA was not affected, although a persistent inhibition of cellular proliferation occurred upon chronic exposure to TPA. The addition of dibutyryl cAMP caused a minor transient increase in hPRL secretion by 35% after 1 h.
Gellersen
B
B
Institute for Hormone and Fertility Research, Hamburg, F.R.G.
DiMattia
G E
GE
Friesen
H G
HG
Bohnet
H G
HG
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D001402:B-Lymphocytes / Q000378:metabolism*; D015152:Blotting, Northern; D003994:Bucladesine / Q000494:pharmacology; D002460:Cell Line; D000242:Cyclic AMP / Q000502:physiology; D004305:Dose-Response Relationship, Drug; D006801:Humans; D011388:Prolactin / Q000378:metabolism*; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D012333:RNA, Messenger / Q000187:drug effects / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*
D012333:RNA, Messenger; D003994:Bucladesine; D011388:Prolactin; D000242:Cyclic AMP; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D015056:1-Methyl-3-isobutylxanthine