Tumor promoters enhance basal and growth hormone releasing factor stimulated cyclic AMP levels in anterior pituitary cells.
Tumor promoters, such as phorbol esters and teleocidin, amplified the ability of growth hormone releasing factor to increase pituitary cyclic AMP levels. This effect of tumor promoters was concentration-dependent, could be observed in 5 minutes, and was over by 4 hours. Inactive tumor promoters (i.e., 4-alpha-didecanoate) had no effect on this system, whereas a synthetic diacylglycerol (i.e., 1-oleoly-2-acetyl glycerol), mimicked the action of tumor promoters. Due to the known stimulation of protein kinase C by both tumor promoters and diacylglycerols, we suggest that this calcium and phospholipid dependent protein kinase C can enhance the ability of the growth hormone releasing factor receptor to activate the cyclic AMP generating system.
Cronin
M J
MJ
Canonico
P L
PL
D000818:Animals; D002273:Carcinogens / Q000494:pharmacology*; D000242:Cyclic AMP / Q000378:metabolism*; D004075:Diglycerides / Q000494:pharmacology; D005260:Female; D013007:Growth Hormone-Releasing Hormone / Q000494:pharmacology*; D066298:In Vitro Techniques; D007700:Kinetics; D008235:Lyngbya Toxins / Q000494:pharmacology; D008297:Male; D010703:Phorbol Esters / Q000494:pharmacology; D010903:Pituitary Gland, Anterior / Q000187:drug effects* / Q000378:metabolism; D011493:Protein Kinase C; D011494:Protein Kinases / Q000378:metabolism; D051381:Rats
D002273:Carcinogens; D004075:Diglycerides; D008235:Lyngbya Toxins; D010703:Phorbol Esters; C022176:teleocidins; C038237:1-oleoyl-2-acetylglycerol; D013007:Growth Hormone-Releasing Hormone; D000242:Cyclic AMP; D011494:Protein Kinases; D011493:Protein Kinase C