Prokaryotic adenylate cyclase toxin stimulates anterior pituitary cells in culture.
Bordetella pertussis synthesizes a variety of virulence factors including a calmodulin-dependent adenylate cyclase (AC) toxin. Treatment of anterior pituitary cells with this AC toxin resulted in an increase in cellular cAMP levels that was associated with accelerated exocytosis of growth hormone (GH), prolactin, adrenocorticotropic hormone (ACTH), and luteinizing hormone (LH). The kinetics of release of these hormones, however, were markedly different; GH and prolactin were rapidly released, while LH and ACTH secretion was more gradually elevated. Neither dopamine agonists nor somatostatin changed the ability of AC toxin to generate cAMP (up to 2 h). Low concentrations of AC toxin amplified the secretory response to hypophysiotrophic hormones. We conclude that bacterial AC toxin can rapidly elevate cAMP levels in anterior pituitary cells and that it is this response that explains the subsequent acceleration of hormone release.
D037361:Adenylate Cyclase Toxin; D000262:Adenylyl Cyclases / Q000494:pharmacology*; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D002147:Calmodulin / Q000502:physiology; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism; D005089:Exocytosis / Q000187:drug effects; D005260:Female; D013006:Growth Hormone / Q000378:metabolism; D066298:In Vitro Techniques; D007700:Kinetics; D007986:Luteinizing Hormone / Q000378:metabolism; D008297:Male; D010903:Pituitary Gland, Anterior / Q000187:drug effects* / Q000378:metabolism; D011388:Prolactin / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D010566:Virulence Factors, Bordetella / Q000494:pharmacology*
D037361:Adenylate Cyclase Toxin; D002147:Calmodulin; D010566:Virulence Factors, Bordetella; D000324:Adrenocorticotropic Hormone; D011388:Prolactin; D007986:Luteinizing Hormone; D013006:Growth Hormone; D000242:Cyclic AMP; D000262:Adenylyl Cyclases