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Species- and tissue-dependent effects of NO and cyclic GMP on cardiac ion channels.
- Source :
-
Comparative biochemistry and physiology. Part A, Molecular & integrative physiology [Comp Biochem Physiol A Mol Integr Physiol] 2005 Oct; Vol. 142 (2), pp. 136-43. Date of Electronic Publication: 2005 May 31. - Publication Year :
- 2005
-
Abstract
- Biochemical studies have established the presence of a NO pathway in the heart, including sources of NO and various effectors. Several cardiac ion channels have been shown to be modified by NO, such as L-type Ca(2+), ATP-sensitive K(+), and pacemaker f-channels. Some of these effects are mediated by cGMP, through the activity of three main proteins: the cGMP-dependent protein kinase (PKG), the cGMP-stimulated phosphodiesterase (PDE2) and the cGMP-inhibited PDE (PDE3). Other effects appear independent of cGMP, as for instance the NO modulation of the ryanodine receptor-Ca(2+) channel. In the case of the cardiac L-type Ca(2+) channel current (I(Ca,L)), both cGMP-dependent and cGMP-independent effects have been reported, with important tissue and species specificity. For instance, in rabbit sinoatrial myocytes, NO inhibits the beta-adrenergic stimulation of I(Ca,L) through activation of PDE2. In cat and human atrial myocytes, NO potentiates the cAMP-dependent stimulation of I(Ca,L) through inhibition of PDE3. In rabbit atrial myocytes, NO enhances I(Ca,L) in a cAMP-independent manner through the activation of PKG. In ventricular myocytes, NO exerts opposite effects on I(Ca,L): an inhibition mediated by PKG in mammalian myocytes but by PDE2 in frog myocytes; a stimulation attributed to PDE3 inhibition in frog ventricular myocytes but to a direct effect of NO in ferret ventricular myocytes. Finally, NO can also regulate cardiac ion channels by a direct action on G-proteins and adenylyl cyclase.
- Subjects :
- Adenylyl Cyclases metabolism
Animals
Calcium chemistry
Calcium metabolism
Cats
Cyclic AMP chemistry
Cyclic AMP metabolism
Cyclic AMP-Dependent Protein Kinases metabolism
Cyclic GMP-Dependent Protein Kinases chemistry
Cyclic GMP-Dependent Protein Kinases metabolism
Heart Diseases metabolism
Heart Ventricles pathology
Humans
Hypertrophy
Ions chemistry
Muscle Cells metabolism
Myocytes, Cardiac metabolism
Nitric Oxide chemistry
Potassium chemistry
Rabbits
Signal Transduction
Tissue Distribution
Cyclic GMP metabolism
Ion Channels chemistry
Myocardium metabolism
Nitric Oxide metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1095-6433
- Volume :
- 142
- Issue :
- 2
- Database :
- MEDLINE
- Journal :
- Comparative biochemistry and physiology. Part A, Molecular & integrative physiology
- Publication Type :
- Academic Journal
- Accession number :
- 15927494
- Full Text :
- https://doi.org/10.1016/j.cbpb.2005.04.012