Subers_1989_J.Biol.Chem_264_19685

Reference

Title : Regulation by high density lipoproteins of muscarinic acetylcholine receptor function in chick heart cells cultured in defined medium - Subers_1989_J.Biol.Chem_264_19685
Author(s) : Subers EM , Nathanson NM
Ref : Journal of Biological Chemistry , 264 :19685 , 1989
Abstract :

Activation of cardiac muscarinic acetylcholine receptors (mAChR) on cultured chick heart cells results in a decrease in cellular cAMP levels and a stimulation of phosphoinositide breakdown. A serum-free culture system has been used to investigate the regulation of mAChR number and function by purified serum high density lipoprotein (HDL). Administration of HDL purified from rooster serum to chick heart cells cultured in defined medium results in an attenuation of the ability of muscarinic agonist to inhibit forskolin-stimulated cAMP accumulation, with no change in its ability to stimulate phosphoinositide hydrolysis or to mediate down-regulation of receptor number. The inclusion of HDL in the culture medium did not result in appreciable changes in mAChR number or affinity, nor were the levels of the inhibitory guanine nucleotide-binding regulatory proteins (G-proteins) altered. However, the ability of guanine nucleotides to inhibit forskolin-stimulated adenylate cyclase activity was reduced by HDL treatment, suggesting that HDL interferes with the capacity of G-proteins to interact with adenylate cyclase. In order to determine which component of native HDL mediates the decreased effectiveness of carbachol, the ability of lipid and apoprotein fractions to mimic the effect of HDL was tested. HDL lipid fractions were able to mimic the effect of native HDL, while protein fractions were not. This result suggests that the ability of HDL to attenuate muscarinic receptor function is mediated by its lipid constituents. The effect of HDL and HDL lipid fractions were not correlated with changes in membrane cholesterol content.

PubMedSearch : Subers_1989_J.Biol.Chem_264_19685
PubMedID: 2555329

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Citations formats

Subers EM, Nathanson NM (1989)
Regulation by high density lipoproteins of muscarinic acetylcholine receptor function in chick heart cells cultured in defined medium
Journal of Biological Chemistry 264 :19685

Subers EM, Nathanson NM (1989)
Journal of Biological Chemistry 264 :19685