Effects of adenosine receptor and muscarinic cholinergic receptor agonists on cardiac protein phosphorylation. Influence of pertussis toxin.
J Neumann, P Bokník, GS Bodor… - The Journal of …, 1994 - jpet.aspetjournals.org
J Neumann, P Bokník, GS Bodor, LR Jones, W Schmitz, H Scholz
The Journal of pharmacology and experimental therapeutics, 1994•jpet.aspetjournals.orgIn isolated 32P-labeled guinea pig ventricular cardiomyocytes phospholamban (PLB),
myosin light chain 2 and the inhibitory subunit of troponin (Tnl) were identified by antibodies.
In isolated 32P-labeled guinea pig ventricular cardiomyocytes isoproterenol (0.1 mumol/l)
increased phosphorylation of PLB and of the inhibitory subunit of Tnl to 159 and 119% of
control, respectively, without effect on the phosphorylation state of myosin light chain 2.
Additionally applied carbachol or (-)-N6-phenylisopropyladenosine reduced …
myosin light chain 2 and the inhibitory subunit of troponin (Tnl) were identified by antibodies.
In isolated 32P-labeled guinea pig ventricular cardiomyocytes isoproterenol (0.1 mumol/l)
increased phosphorylation of PLB and of the inhibitory subunit of Tnl to 159 and 119% of
control, respectively, without effect on the phosphorylation state of myosin light chain 2.
Additionally applied carbachol or (-)-N6-phenylisopropyladenosine reduced …
Abstract
In isolated 32P-labeled guinea pig ventricular cardiomyocytes phospholamban (PLB), myosin light chain 2 and the inhibitory subunit of troponin (Tnl) were identified by antibodies. In isolated 32P-labeled guinea pig ventricular cardiomyocytes isoproterenol (0.1 mumol/l) increased phosphorylation of PLB and of the inhibitory subunit of Tnl to 159 and 119% of control, respectively, without effect on the phosphorylation state of myosin light chain 2. Additionally applied carbachol or (-)-N6-phenylisopropyladenosine reduced phosphorylation of PLB and Tnl without reducing cyclic AMP content. After pretreatment of guinea pigs with pertussis toxin (18 micrograms/100 g b.wt.), carbachol or (-)-N6-phenylisopropyladenosine failed to reduce isoproterenol-stimulated phosphorylation of both PLB and Tnl. It is concluded that the reductions by carbachol and (-)-N6-phenylisopropyladenosine of isoproterenol-stimulated PLB phosphorylation and Tnl phosphorylation are pertussis toxin-sensitive.
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