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Chronic exposure to low doses of HgCl2 avoids the impaired on calcium handling in the right ventricle after myocardial infarction in rat (547.3)
Author(s) -
Stefa Ivanita,
Faria Thais,
Costa Gustavo,
Almenara Camila,
Angeli Jhuli,
Padilha Alessandra,
Vassallo Dalton,
Vassallo Paula
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.547.3
Subject(s) - ventricle , chemistry , calcium , medicine , endocrinology , isometric exercise , contraction (grammar) , cardiac function curve , myocardial infarction , infarction , cardiology , heart failure
The aim of this study was to investigate if chronic exposure to low doses of mercury chloride (HgCl 2 ) causes functional alterations in right ventricle (RV) strips after myocardial infarction (MI). Male Wistar rats were divided into four groups: Control (vehicle); HgCl 2 (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 HgCl 2 ‐MI group. One week after MI RV strips, superfused with Krebs solution, were studied using an isometric tension system. Contractile function of HgCl 2 group did not change compared to Control. On basal conditions, despite similar maximum isometric force at L‐max, relaxation time was reduced in the MI group but preserved in the HgCl 2 ‐MI compared to Control group. The MI group presented a depression in the tetanic peak and plateau of developed force. Additionally, impaired sarcoplasmic reticulum (SR) function and a reduced sarcolemmal calcium influx were observed only in MI animals. The SERCA2a protein expression was reduced in both MI groups while PLB protein expression was increased only in MI group. These results suggest that chronic exposure to low doses of HgCl 2 avoids the impaired SR function and the reduced sarcolemmal calcium influx observed in MI probably acting on PLB and SERCA2a protein expression. Grant Funding Source : Supported by: PRONEX ‐ FAPES, CNPq, CAPES