title: Effects of tumor promoters (mezerein, teleocidin and palytoxin) on growth hormone secretion from rat anterior pituitary cells cultured in monolayer.
abstract: The effects of compounds with tumor promoting activity (mezerein, teleocidin and palytoxin) on rat growth hormone (rGH) release was compared to that of TPA (12-O-tetradecanoyl phorbol-13-acetate). Mezerein and teleocidin both of which are activators of protein kinase C (TPA type tumor promoter), elicited rGH release about 3.5 to 4 fold above control values. The ED 50 was 16 nM for mezerein, 1.1 nM for teleocidin and 1.5 nM for TPA. In contrast to mezerein or teleocidin, a non-TPA type tumor promoter (palytoxin) which does not activate protein kinase C failed to stimulate rGH release. These observations suggest that the activation of protein kinase C is essential in the release of rGH induced by the tumor promoters.
mesh_terms: D000178:Acrylamides; D000818:Animals; D002273:Carcinogens; D002478:Cells, Cultured; D003064:Cnidarian Venoms / Q000494:pharmacology*; D004224:Diterpenes; D004789:Enzyme Activation / Q000187:drug effects; D013006:Growth Hormone / Q000378:metabolism*; D008235:Lyngbya Toxins / Q000494:pharmacology*; D008297:Male; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013729:Terpenes / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D000095702:Polyether Toxins
chemical_list: D000178:Acrylamides; D002273:Carcinogens; D003064:Cnidarian Venoms; D004224:Diterpenes; D013006:Growth Hormone; D008235:Lyngbya Toxins; D011493:Protein Kinase C; D013729:Terpenes; D013755:Tetradecanoylphorbol Acetate; C022176:teleocidins; C011309:mezerein; C010272:palytoxin; D000095702:Polyether Toxins