| Developmental changes in modulation of contractility of rabbit hearts. | |
| | |
MedLine Citation:
|
PMID: 7538615 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
|
We recently described postnatal developmental differences of beta-adrenergic- and G-protein-mediated modulation of L-type calcium currents (ICa) in newborn and adult rabbit heart. To extend the results obtained by ICa experiments, we studied developmental changes in modulation of contractility induced by isoproterenol (ISO), forskolin (FOR) and isobutyl-methylxanthine (IBMX), all of which work through the cyclic AMP-dependent pathway. Left ventricular developed pressure (LVDP) and its first derivative (dP/dt) were measured with an intraventricular fluid-filled balloon in isolated adult and newborn (ages 1-3 days) rabbit hearts under Langendorff perfusion. ISO increased LVDP and +/- dP/dtmax dose dependently, with much greater positive inotropic effect on adult than on newborn heart. Concomitant use of a subthreshold concentration of IBMX (0.1 microM), a nonselective phosphodiesterase inhibitor (PDEI), did not significantly potentiate the dose-dependent inotropic effect of ISO in adult heart, but did markedly potentiate such effect in newborn heart. ISO 10 microM and FOR 10 microM had comparable inotropic effects on adult heart, whereas 10 microM ISO had a much weaker inotropic effect than 10 microM FOR on newborn heart. However, the increase in LVDP and +dP/dtmax and the percentage increase in these values induced by 10 microM FOR in newborn heart was still significantly lower than that in adult heart. Newborn heart has less effective signal transduction from beta-adrenergic stimulation (ISO) to increased contractility than does adult heart. Although newborn heart responds more to direct stimulation of adenylyl cyclase activity (FOR) than to beta-adrenergic stimulation, it still has less overall contractile reserve than adult heart. PDE isozymes of newborn heart are much more sensitive to IBMX than are those of adult heart, producing a significant potentiation of ISO effect by low doses of IBMX in newborn, but not adult, heart. |
| | |
Authors:
|
T Akita; R Kumar; R W Joyner |
Related Documents
:
|
22330945 - High pressure treatments on the inactivation of salmonella enteritidis and the physicoc... 22493075 - Influence of high glycemic index and glycemic load diets on blood pressure during adole... 22287465 - The impact of intraoperative saline irrigations on bacterial load within the maxillary ... 582695 - Pharmacological studies on 3-[gamma-(p-fluorobenzoyl)propyl]-2,3,4,4a,5,6-hexahydro-1 (... 19902055 - Changed duration of ventricle repolarization in dog heart under conditions of increased... 21246205 - Mitochondrial complex i and nad(p)h oxidase are major sources of exacerbated oxidative ... |
Publication Detail:
|
Type: Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
Journal Detail:
|
Title: Journal of cardiovascular pharmacology Volume: 25 ISSN: 0160-2446 ISO Abbreviation: J. Cardiovasc. Pharmacol. Publication Date: 1995 Feb |
Date Detail:
|
Created Date: 1995-06-22 Completed Date: 1995-06-22 Revised Date: 2007-11-14 |
Medline Journal Info:
|
Nlm Unique ID: 7902492 Medline TA: J Cardiovasc Pharmacol Country: UNITED STATES |
Other Details:
|
Languages: eng Pagination: 240-51 Citation Subset: IM |
Affiliation:
|
Todd Franklin Cardiac Research Laboratory, Department of Pediatrics, Emory University School of Medicine, Atlanta, GA 30322, USA. |
Export Citation:
|
APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
|
1-Methyl-3-isobutylxanthine
/
pharmacology* Adenylate Cyclase / metabolism Aging / physiology* Animals Animals, Newborn Blood Pressure / drug effects Cyclic AMP / pharmacology Dose-Response Relationship, Drug Forskolin / pharmacology* Heart Ventricles / drug effects Isoproterenol / pharmacology* Myocardial Contraction / drug effects* Phosphodiesterase Inhibitors / pharmacology Rabbits Receptors, Adrenergic, beta / metabolism Signal Transduction / drug effects Ventricular Function, Left / drug effects |
| Grant Support | |
ID/Acronym/Agency:
|
HL22562/HL/NHLBI NIH HHS; HL27385/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
|
0/Phosphodiesterase Inhibitors; 0/Receptors, Adrenergic, beta; 28822-58-4/1-Methyl-3-isobutylxanthine; 60-92-4/Cyclic AMP; 66428-89-5/Forskolin; 7683-59-2/Isoproterenol; EC 4.6.1.1/Adenylate Cyclase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
Previous Document: Characterization of cilia-associated respiratory bacillus in rabbits and analysis of the 16S rRNA ge...
Next Document: The insulin-like growth factor system in regulation of normal and malignant hematopoiesis.