Universidade Federal de Santa Maria

About: Universidade Federal de Santa Maria is a education organization based out in Santa Maria, Brazil. It is known for research contribution in the topics: Population & Context (language use). The organization has 21178 authors who have published 35632 publications receiving 371665 citations.

Oxidative stress versus antioxidant defenses in patients with acute myocardial infarction.

Abstract: Acute myocardial infarction (AMI) is a highly dynamic event, which is associated with increasing production of reactive oxygen species (ROS). The imbalance between ROS production and antioxidant defenses leads to the condition known as oxidative stress. The most widely recognized effect of increasing oxidative stress is the oxidation and damage of macromolecules, membranes, proteins, and DNA. Therefore, in this study we sought to evaluate oxidative stress and antioxidant defenses in patients with AMI. Lipid peroxidation, protein carbonyl levels, and enzymatic and nonenzymatic antioxidants were assessed in samples obtained from 40 AMI patients and 40 control patients. AMI was characterized by clinical, electrocardiographic, and laboratory criteria. The control group was divided into two groups of 20 patients: a control group with healthy patients and a risk group. Our results demonstrated an increase in substances reactive to thiobarbituric acid (TBARS) and carbonyl protein levels in the AMI and risk groups. In addition, a positive correlation was found between TBARS, carbonyl protein levels, and troponin I in AMI patients. Surprisingly, for the enzymatic antioxidant defenses, catalase and superoxide dismutase, we observed an increase in these parameters in the AMI and risk groups when compared with healthy patients. However, a decrease in nonenzymatic antioxidants such as vitamin C and vitamin E was observed in AMI patients when compared with the healthy group and the risk group. The increase in oxidative stress was probably a result of the elevation in ROS production due to the ischemic/reperfusion event that occurs in AMI, in addition to the decrease of nonenzymatic antioxidant defenses.