Risk Factors of Acute Myocardial Infarction in Rats Under Combined Exposure to Ethanol and Methylmercury

Marília Sakamoto  Peixotoa, Lacy Cardoso  de  Brito Junior b,  José Luiz  Fernandes Vieirac, Fabiana  Pirani

Carneirod, João Batista de Sousad, Vania Maria Moraes Ferreiraa*

ABSTRACT

The consumption  of moderate  doses  of ethanol  (EtOH) can  be  useful in the prevention of cardiovascular events.  In contrast,  methylmercury (MeHg) has  been  associated  with myocardial  infarction.  However,  the combined  exposure to these  neurotoxicants needs  to be  taken  into consideration.  Our  objective, therefore, was  to  evaluate  the  biochemical  alterations  in  animals  that  received  EtOH  and/or  MeHg  during  their intrauterine life as risk factors for acute myocardial infarction. Pregnant rats received tap water or EtOH during pregnancy  and  breast-feeding.  On  the 15th   day of pregnancy,  half of the treatment groups  received MeHg. The  offspring  groups   were:  Control,  EtOH,  MeHg,  and   EtOH+MeHg   and   were  evaluated   during  an exhaustive swimming test. The results suggest  the adult  rat offspring that  received  only MeHg during  their intra-uterine life were more susceptible to acute myocardial infarction after exhaustive activity than the groups that  received  EtOH  or  EtOH+MeHg.   The MeHg  group  displayed  an  increase  in almost  all  biochemical parameters,  especially levels of the enzymes CPK and  CKMB. Our  data  complement  research  related  to the risk of acute  infarction of the myocardium and  the effect of EtOH and/or MeHg on that risk. However, the exact cytoprotective mechanism of EtOH against the effect of MeHg needs further investigation.

KEYWORDS:  biochemistry; exhaustive swimming test;  fetal  alcohol  syndrome;  methylmercury; myocardial infarction.