Incubation of cultured embryonic chicken heart cells with the -adrenergic agonist isoproterenol resulted in a dose-dependent increase in the number of mAChR on the surface of intact cells. The isoproterenol-mediated increase in mAChR number was time dependent and reached a maximum by 48 h. Chick heart cells treated with isoproterenol exhibited a greater than 6-fold increase in the sensitivity for carbachol-mediated inhibition of adenylyl cyclase activity as compared to control. Stimulation of cultured heart cells for 24 h with isoproterenol resulted in a 25-35% increase in cm2 mRNA levels as compared to control cm2 mRNA levels. In contrast, the level of cm4 mRNA was not significantly affected by isoproterenol treatment. cm2 mRNA levels were maximally elevated by 15 h following isoproterenol stimulation and remained elevated for up to 72 h. Incubation of cells with isoproterenol in the presence of Rp-cAMP, an inhibitor of cAMP-dependent protein kinase, blocked the increase in the level of cm2 mRNA. Thus, prolonged activation of -adrenergic receptors results in an increase in mAChR number and muscarinic responsiveness in chick heart cells due to a cAMP-dependent protein kinase mediated increase in cm2 mRNA levels.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				J. Grima and C. Y. Cheng Testin Induction: The Role of Cyclic 3',5'-Adenosine Monophosphate/Protein Kinase A Signaling in the Regulation of Basal and Lonidamine-Induced Testin Expression by Rat Sertoli Cells Biol Reprod, December 1, 2000; 63(6): 1648 - 1660. [Abstract] [Full Text]

				J. C. W. Mak, A. F. Roffel, T. Katsunuma, C. R. S. Elzinga, J. Zaagsma, and P. J. Barnes Up-Regulation of Airway Smooth Muscle Histamine H1 Receptor mRNA, Protein, and Function by beta 2-Adrenoceptor Activation Mol. Pharmacol., May 1, 2000; 57(5): 857 - 864. [Abstract] [Full Text]

				T. Katsunuma, A. F. Roffel, C. R. S. Elzinga, J. Zaagsma, P. J. Barnes, and J. C. W. Mak beta 2-Adrenoceptor Agonist-Induced Upregulation of Tachykinin NK2 Receptor Expression and Function in Airway Smooth Muscle Am. J. Respir. Cell Mol. Biol., September 1, 1999; 21(3): 409 - 417. [Abstract] [Full Text]

				L. A. McKinnon, E. C. Gunther, and N. M. Nathanson Developmental Regulation of the cm2 Muscarinic Acetylcholine Receptor Gene: Selective Induction by a Secreted Factor Produced by Embryonic Chick Retinal Cells J. Neurosci., January 1, 1998; 18(1): 59 - 69. [Abstract] [Full Text] [PDF]