+ Site Statistics
+ Search Articles
+ PDF Full Text Service
How our service works
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ Translate
+ Recently Requested

Muscarinic cholinergic receptor-mediated attenuation of adenylate cyclase activity in rat heart membranes



Muscarinic cholinergic receptor-mediated attenuation of adenylate cyclase activity in rat heart membranes



Journal of Cyclic Nucleotide and Protein Phosphorylation Research 10(2): 197-210



The regulation of adenylate cyclase by muscarinic cholinergic receptors has been studied in rat heart membranes. In the presence of isoproterenol the K0.5 for Mg2+-mediated activation of adenylate cyclase was 0.1 mM; the addition of the muscarinic receptor agonist oxotremorine increased the K0.5 for Mg2+, and activation by Mg2+ no longer followed mass action kinetics for a single site interaction. The extent of oxotremorine-mediated attenuation of adenylate cyclase exhibited a Mg2+ concentration dependence: in short-time assays at 0.25 mM free Mg2+ the attenuation of enzyme activity was 55 percent, whereas at 20mM Mg2+, only 20 percent inhibition was observed. The increase in the apparent K0.5 for Mg2+ in the presence of oxotremorine was less in 20 min assays than in 4 min assays. The effects of oxotremorine on the rates of activation and deactivation of adenylate cyclase also were examined. Oxotremorine increased the rate of deactivation of adenylate cyclase by two-fold. At low free Mg2+ concentrations, oxotremorine also decreased the rate of activation of adenylate cyclase in the presence of either 0.1 uM GTP gamma S or 1 uM GTP. An oxotremorine-mediated decrease in the rate of activation of adenylate cyclase activity was not detectable in the presence of greater than 3 mM Mg2+.

Please choose payment method:






(PDF emailed within 1 workday: $29.90)

Accession: 040755840

Download citation: RISBibTeXText

PMID: 3998232


Related references

Muscarinic cholinergic receptor mediated inhibitory transduction of adenylate cyclase activity in subcellular fractions from rat heart improved detection in sodium phosphate buffer. Molecular & Cellular Biochemistry 93(1): 35-46, 1990

Autonomic interactions in the aging heart: age-associated decrease in muscarinic cholinergic receptor mediated inhibition of beta-adrenergic activation of adenylate cyclase. Mechanisms of Ageing and Development 34(3): 249-259, 1986

Comparison of muscarinic receptor mediated inhibition of adenylate cyclase activity in the corpus striatum and heart. FASEB Journal 3(4): A1285, 1989

Agonist regulation of adenylate cyclase activity in neuroblastoma x glioma hybrid NG108-15 cells transfected to co-express adenylate cyclase type II and the beta 2-adrenoceptor. Evidence that adenylate cyclase is the limiting component for receptor-mediated stimulation of adenylate cyclase activity. Biochemical Journal 318: 1033-1039, 1996

Positive coupling of cholinergic muscarinic receptors to adenylate cyclase activity in membranes of rat olfactory bulb. Naunyn-Schmiedeberg's Archives of Pharmacology 342(1): 107-109, 1990

Reconstitution of muscarinic cholinergic inhibition of adenylate cyclase activity in embryonic chick heart. Journal of the American College of Cardiology 9(2 Suppl. A): 134A, 1987

Muscarinic cholinergic receptor modulation of beta adrenergic receptor affinity for catecholamines and catecholamine stimulation of adenylate cyclase activity. Clinical Research 26(3): 486A, 1978

Effects of muscarinic cholinergic receptor agonists on beta adrenergic and histamine h 2 receptor stimulated adenylate cyclase activity in guinea pig myo cardium. Clinical Research 30(4): 816A, 1982

Depression of canine cardiac adenylate cyclase activity by muscarinic cholinergic agonists evidence that the effect is mediated by acceleration of the rate of decay of enzyme activity. Clinical Research 29(2): 244A, 1981

A receptor reserve for muscarinic inhibition of adenylate cyclase activity in rat striatal membranes. British Journal Of Pharmacologyppl: 79p, 1987

Adenylate cyclase activity of synaptic membranes from rat striatum. Inhibition by muscarinic receptor agonists. Molecular Pharmacology 23(2): 393-398, 1983

Muscarinic cholinergic-receptor stimulation of specific GTP hydrolysis related to adenylate cyclase activity in canine cardiac sarcolemma. Circulation Research 63(2): 340-350, 1988

Desensitization of turkey erythrocyte adenylate cyclase. Beta-adrenergic receptor phosphorylation is correlated with attenuation of adenylate cyclase activity. Journal of Biological Chemistry 259(15): 9742-9749, 1984

Differences between atria and ventricles in muscarinic receptor mediated inhibition of adenylate cyclase activity. FASEB Journal 6(4): A1311, 1992