Effect of pertussis toxin on the hormonal regulation of cyclic AMP levels in hamster fat cells.
Pertussis toxin was purified approx. 1800-fold from pertussis vaccine. Administration of as little as 1 microgram of toxin/100 g body weight to hamsters markedly decreased the sensitivity of their adipocytes to agents that inhibit adenylate cyclase through receptor-mediated, GTP-dependent mechanisms such as alpha 2-adrenergic amines, prostaglandins, phenylisopropyladenosine and nicotinic acid. On the contrary, the inhibitory effect of 2',5'-dideoxyadenosine on cyclic AMP accumulation was not affected by the toxin. Activation of adenylate cyclase by isoproterenol, ACTH or forskolin was not diminished by the toxin but the maximum cyclic AMP accumulation was consistently increased. Furthermore, the dose-response curves for ACTH and forskolin were clearly shifted to the left in adipocytes from toxin-treated hamsters as compared to control adipocytes. It is concluded that pertussis toxin blocks the transfer of inhibitory information from the receptors to adenylate cyclase.
D037361:Adenylate Cyclase Toxin; D000262:Adenylyl Cyclases / Q000378:metabolism; D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology; D000818:Animals; D001427:Bacterial Toxins / Q000302:isolation & purification / Q000494:pharmacology*; D001886:Bordetella pertussis; D003000:Clonidine / Q000494:pharmacology; D006224:Cricetinae; D000242:Cyclic AMP / Q000378:metabolism*; D015232:Dinoprostone; D004837:Epinephrine / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D007700:Kinetics; D009539:Nicotinic Acids / Q000494:pharmacology; D037342:Pertussis Toxin; D011458:Prostaglandins E / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000378:metabolism; D010566:Virulence Factors, Bordetella
D037361:Adenylate Cyclase Toxin; D001427:Bacterial Toxins; D009539:Nicotinic Acids; D011458:Prostaglandins E; D011943:Receptors, Adrenergic, beta; D010566:Virulence Factors, Bordetella; D000324:Adrenocorticotropic Hormone; D000242:Cyclic AMP; D037342:Pertussis Toxin; D000262:Adenylyl Cyclases; D015232:Dinoprostone; D007545:Isoproterenol; D003000:Clonidine; D004837:Epinephrine