title: Chronic exposure to low doses of HgCl2 avoids calcium handling impairment in the right ventricle after myocardial infarction in rats.
abstract: Right ventricle systolic dysfunction is a major risk factor for death and heart failure after myocardial infarction (MI). Heavy metal exposure has been associated with the development of several cardiovascular diseases, such as MI. The aim of this study was to investigate whether chronic exposure to low doses of mercury chloride (HgCl2) enhances the functional deterioration of right ventricle strips after MI. Male Wistar rats were divided into four groups: Control (vehicle); HgCl2 (exposure during 4 weeks- 1st dose 4.6 µg/kg, subsequent dose 0.07 µg/kg/day, i.m. to cover daily loss); MI surgery induced and HgCl2-MI groups. One week after MI, the morphological and hemodynamic measurements and isometric tension of right ventricle strips were investigated. The chronic HgCl2 exposure did not worsen the injury compared with MI alone in the morphological or hemodynamic parameters evaluated. At basal conditions, despite similar maximum isometric force at L-max, relaxation time was increased in the MI group but unaffected in the HgCl2-MI compared to the Control group. Impairment of the sarcoplasmic reticulum (SR) function and reduction in the sarcolemmal calcium influx were observed in MI group associated with SERCA2a reduction and increased PLB protein expression. Induction of MI in chronic HgCl2 exposed rats did not cause any alteration in the developed force at L-max, lusitropic function or -dF/dt except for a tendency of a reduction SR function. These findings could be partially explained by the normalization in the sarcolemmal calcium influx and the increase in NCX protein expression observed only in this group. These results suggest that chronic exposure to low doses of HgCl2 prevents the impaired SR function and the reduced sarcolemmal calcium influx observed in MI likely by acting on NCX, PLB and SERCA2a protein expression.
authors.affiliation: Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, Brazil.
authors.forename: Thaís de Oliveira
authors.initials: Tde O
authors.lastname: Faria
authors.affiliation: Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, Brazil.
authors.forename: Gustavo Pinto
authors.initials: GP
authors.lastname: Costa
authors.affiliation: Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, Brazil.
authors.forename: Camila Cruz Pereira
authors.initials: CC
authors.lastname: Almenara
authors.affiliation: Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, Brazil.
authors.forename: Jhuli Keli
authors.initials: JK
authors.lastname: Angeli
authors.affiliation: Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, Brazil; Escola de Ensino Superior da Santa Casa de Misericórdia de Vitória, EMESCAM, Vitória, Brazil.
authors.forename: Dalton Valentim
authors.initials: DV
authors.lastname: Vassallo
authors.affiliation: Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, Brazil.
authors.forename: Ivanita
authors.initials: I
authors.lastname: Stefanon
authors.affiliation: Departamento de Ciências Fisiológicas, Universidade Federal do Espírito Santo, Vitória, Brazil.
authors.forename: Paula Frizera
authors.initials: PF
authors.lastname: Vassallo
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004195:Disease Models, Animal; D006352:Heart Ventricles / Q000378:metabolism* / Q000503:physiopathology*; D006439:Hemodynamics; D008297:Male; D008627:Mercuric Chloride / Q000008:administration & dosage*; D009200:Myocardial Contraction / Q000187:drug effects; D009203:Myocardial Infarction / Q000378:metabolism* / Q000473:pathology / Q000503:physiopathology*; D051381:Rats; D012519:Sarcoplasmic Reticulum / Q000187:drug effects / Q000378:metabolism; D016278:Ventricular Function, Right / Q000187:drug effects*
chemical_list: D008627:Mercuric Chloride; D002118:Calcium
references.citation: Br J Pharmacol. 2011 Apr;162(8):1819-31
references.pmid: 21232032
references.citation: Cardiovasc Res. 1990 Sep;24(9):748-53
references.pmid: 2146021
references.citation: Pharmacol Rep. 2008 Jan-Feb;60(1):119-26
references.pmid: 18276993
references.citation: J Clin Invest. 2005 Mar;115(3):556-64
references.pmid: 15765137
references.citation: Annu Rev Physiol. 2008;70:23-49
references.pmid: 17988210
references.citation: Life Sci. 2006 Sep 13;79(16):1537-45
references.pmid: 16716361
references.citation: Nature. 1983 Aug 25-31;304(5928):735-8
references.pmid: 6888540
references.citation: Circ Res. 1979 Apr;44(4):503-12
references.pmid: 428047
references.citation: Annu Rev Physiol. 2014;76:107-27
references.pmid: 24245942
references.citation: Cardiovasc Res. 2003 Jun 1;58(3):621-31
references.pmid: 12798435
references.citation: Environ Health Perspect. 1987 Nov;75:59-64
references.pmid: 3319566
references.citation: Altern Ther Health Med. 2007 Mar-Apr;13(2):S128-33
references.pmid: 17405690
references.citation: N Engl J Med. 2002 Nov 28;347(22):1747-54
references.pmid: 12456850
references.citation: Braz J Med Biol Res. 1999 Aug;32(8):989-97
references.pmid: 10454761
references.citation: PLoS One. 2013 May 31;8(5):e64986
references.pmid: 23741440
references.citation: Curr Cardiol Rev. 2013 Feb 1;9(1):73-81
references.pmid: 23092273
references.citation: Toxicol Appl Pharmacol. 2011 Sep 1;255(2):193-9
references.pmid: 21723307
references.citation: J Am Coll Cardiol. 2002 May 1;39(9):1450-5
references.pmid: 11985906
references.citation: Arch Med Res. 2011 May;42(4):274-80
references.pmid: 21820605
references.citation: Ind Health. 1996;34(4):421-5
references.pmid: 8908853
references.citation: Comp Biochem Physiol C Toxicol Pharmacol. 2008 Mar;147(2):252-60
references.pmid: 18093879
references.citation: J Am Coll Cardiol. 1998 Dec;32(7):2035-42
references.pmid: 9857890
references.citation: Circulation. 1995 Feb 1;91(3):645-55
references.pmid: 7828289
references.citation: Circulation. 2013 Jan 1;127(1):e6-e245
references.pmid: 23239837
references.citation: Toxicol Appl Pharmacol. 1999 Apr 15;156(2):113-8
references.pmid: 10198276
references.citation: Braz J Med Biol Res. 2011 Sep;44(9):939-46
references.pmid: 21845340
references.citation: Eur Heart J. 2008 Apr;29(7):932-40
references.pmid: 18334475
references.citation: Circulation. 1990 Apr;81(4):1161-72
references.pmid: 2138525
references.citation: Braz J Med Biol Res. 2011 Sep;44(9):890-8
references.pmid: 21829898
references.citation: Comp Biochem Physiol C Toxicol Pharmacol. 2003 Jul;135C(3):269-75
references.pmid: 12927901
references.citation: Braz J Med Biol Res. 2013 Feb;46(2):178-85
references.pmid: 23369976
references.citation: Clin Chem. 2005 Apr;51(4):759-67
references.pmid: 15695327
references.citation: J Clin Hypertens (Greenwich). 2011 Aug;13(8):621-7
references.pmid: 21806773
references.citation: Environ Res. 2013 May;123:25-32
references.pmid: 23472608
references.citation: N Engl J Med. 2011 Mar 24;364(12):1116-25
references.pmid: 21428767
references.citation: Arch Pathol Lab Med. 1991 Jan;115(1):56-60
references.pmid: 1987914
references.citation: Diab Vasc Dis Res. 2012 Jul;9(3):170-6
references.pmid: 22752941
references.citation: Br J Sports Med. 2008 Dec;42(12):950-2
references.pmid: 18838401
references.citation: Clin Radiol. 2001 Jan;56(1):17-21
references.pmid: 11162692
references.citation: Am J Cardiol. 2008 Mar 1;101(5):607-12
references.pmid: 18308007