| Arachidonic acid enhances contraction and intracellular Ca2+ transients in individual rat ventricular myocytes. | |
| | |
MedLine Citation:
|
PMID: 9038956 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
Modulation of intracellular free Ca2+ concentration ([Ca2+]i) by inotropic stimuli alters contractility in cardiac muscle. Arachidonic acid (AA), a precursor for eicosanoid formation, is released in response to receptor activation and myocardial ischemia and has been demonstrated to alter K+ and Ca2+ channel activity. We investigated the effects of AA on contractility by simultaneously measuring [Ca2+]i and shortening in single field-stimulated rat ventricular myocytes. [Ca2+]i transients were measured using fura 2, and myocyte shortening was assessed using video edge detection. AA stimulated a doubling in the amplitude of the [Ca2+]i transient and a twofold increase in myocyte shortening. In addition, AA stimulated a 30% increase in the time to 50% diastolic [Ca2+]i and a 35% increase in the time to 50% relengthening. These effects of AA were mediated by AA itself (56 +/- 5%) and by cyclooxygenase metabolites. Pretreatment with the protein kinase C inhibitors staurosporine and chelerythrine nearly abolished (> 90% inhibition) these AA-induced effects. Inhibition of voltagegated K+ channels with 4-aminopyridine mimicked the effects of AA. Addition of AA to the 4-aminopyridine-treated myocyte had no additional effect on parameters of contractile function. These data indicate that AA alters the amplitude and duration of Ca2- transients and myocyte shortening via protein kinase C-dependent inhibition of voltage-gated K+ channels. Release of AA by phospholipases in response to receptor activation by endogenous mediators or pathological stimuli may be involved in mediating inotropic responses in cardiac muscle. |
| | |
Authors:
|
D S Damron; B A Summers |
Related Documents
:
|
3421716 - Lethal injury by diquat redox cycling in an isolated hepatocyte model. 8147266 - Interactions of bradykinin, calcium, g-protein and protein kinase in the activation of ... 2116176 - A calcium-independent 5-lipoxygenase system in mast/basophil pt-18 cells. 8385946 - Regulatory effect of arachidonic acid on the calcium transport system in rat liver nuclei. 6822296 - Contraction, membrane potential, and calcium fluxes in rabbit pulmonary arterial muscle. 15695246 - Post-tetanic potentiation in the rat calyx of held synapse. |
Publication Detail:
|
Type: Journal Article; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
|
Title: The American journal of physiology Volume: 272 ISSN: 0002-9513 ISO Abbreviation: Am. J. Physiol. Publication Date: 1997 Jan |
Date Detail:
|
Created Date: 1997-03-31 Completed Date: 1997-03-31 Revised Date: 2007-11-14 |
Medline Journal Info:
|
Nlm Unique ID: 0370511 Medline TA: Am J Physiol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: H350-9 Citation Subset: IM |
Affiliation:
|
Center for Anesthesiology Research, Cleveland Clinic Foundation, Ohio 44195, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
4-Aminopyridine
/
pharmacology Animals Arachidonic Acid / pharmacology* Calcium / metabolism* Cyclooxygenase Inhibitors / pharmacology Cytochrome P-450 Enzyme System / antagonists & inhibitors Enzyme Inhibitors / pharmacology Heart Ventricles Intracellular Membranes / drug effects, metabolism* Lipoxygenase Inhibitors / pharmacology Myocardial Contraction / drug effects* Myocardium / cytology, metabolism* Phosphotransferases / antagonists & inhibitors Rats |
| Grant Support | |
ID/Acronym/Agency:
|
HL-08726/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Cyclooxygenase Inhibitors; 0/Enzyme Inhibitors; 0/Lipoxygenase Inhibitors; 504-24-5/4-Aminopyridine; 506-32-1/Arachidonic Acid; 7440-70-2/Calcium; 9035-51-2/Cytochrome P-450 Enzyme System; EC 2.7.-/Phosphotransferases |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Regional glucose uptake within hypoperfused swine myocardium as measured by positron emission tomogr...
Next Document: Myocardial infarction alters myofilament calcium sensitivity and mechanical behavior of myocytes.