Regulation of muscle differentiation: stimulation of myoblast fusion in vitro by catecholamines.
Epinephrine and isoproterenol provoke primary chick myoblasts to initiate precocious cell fusion. Both the rise in intracellular adenosine 3' ,5-monophosphate (cyclic AMP) and cell fusion generated by these effectors are prevented by propranolol, which is a specific blocker of the beta-adrenergic receptor. Propranolol has no effect either on the precocious cell fusion provoked by prostaglandin E or on cell fusion in control cultures. The results support the idea that a rise in cyclic AMP is the critical intracellular change responsible for initiating events that culminate in myoblast differentiation 4 to 5 hours later. They also indicate that the culminate in myoblast differentiation 4 to 5 hours later. They also indicate that the hormone responsible for the positive regulation of myoblast differentiation in vitro is not acting through the beta-adrenergic receptor.
D000818:Animals; D002395:Catecholamines / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002459:Cell Fusion / Q000187:drug effects*; D002478:Cells, Cultured; D002642:Chick Embryo; D000242:Cyclic AMP / Q000378:metabolism; D004837:Epinephrine / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D009132:Muscles / Q000166:cytology*; D011433:Propranolol / Q000494:pharmacology; D011458:Prostaglandins E / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000187:drug effects; D013268:Stimulation, Chemical
D002395:Catecholamines; D011458:Prostaglandins E; D011943:Receptors, Adrenergic, beta; D011433:Propranolol; D000242:Cyclic AMP; D007545:Isoproterenol; D004837:Epinephrine