Document Detail


Effects of mercury on the contractile activity of the right ventricular myocardium.
MedLine Citation:
PMID:  11503076     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
The increase in right ventricular systolic pressure observed in vivo after the administration of mercury opposes to the idea that the metal depresses the cardiac pump performance. We then investigated the effects of HgCl(2) (0.1 to 2.5 microM) on the contractile activity of the right ventricular myocardium, measuring isometric and tetanic contractions of right ventricular isolated strips, right ventricular isovolumic systolic and diastolic pressures, and the coronary perfusion pressure (0.03 to 3 microM) in constant-flow Langendorff-perfused rat hearts. The results presented here suggest that the acute effects of mercury on the right ventricular myocardium are distinct. When isolated strips of right ventricular wall are used, the contractile depression produced by mercury is manifested. However, when mercury is administered to isolated perfused hearts or in vivo this depressant effect is not revealed. The possible reasons for this behavior are the increased coronary perfusion pressure, which promotes a positive inotropic effect, manifested during the infusion of increasing concentrations of mercury, or the putative stretch of the ventricular fibers, which might cause the increment of diastolic pressure. An interesting finding is that the mechanical activity of the preparations, in which mercury is administered via coronary circulation, is not depressed and, even more, it can increase systolic pressure. However, the nature of this protective effect of coronary circulation cannot be explained by the results presented here.
Authors:
F N Cunha; G P de Assis; C E Silva; I Stefanon; V D Pinto; D V Vassallo
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Archives of environmental contamination and toxicology     Volume:  41     ISSN:  0090-4341     ISO Abbreviation:  Arch. Environ. Contam. Toxicol.     Publication Date:  2001 Oct 
Date Detail:
Created Date:  2001-08-14     Completed Date:  2001-10-04     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0357245     Medline TA:  Arch Environ Contam Toxicol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  374-80     Citation Subset:  IM    
Affiliation:
Department of Physiological Sciences, Federal University of Espirito Santo and Health Science Center of Vitória-EMESCAM, Vitoria, ES, Brazil.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure / drug effects*
Culture Techniques
Environmental Pollutants / adverse effects*
Male
Mercury / adverse effects*
Myocardial Contraction / drug effects*
Rats
Rats, Wistar
Chemical
Reg. No./Substance:
0/Environmental Pollutants; 7439-97-6/Mercury

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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