EFFECTS OF MYOCARDIAL-INFARCTION AND CAPTOPRIL THERAPY ON ANXIETY-RELATED BEHAVIORS IN THE RAT

The angiotensin-converting enzyme inhibitor, captopril, is used in the treatment of heart failure after myocardial infarction. This study ev aluated whether different behavioral parameters of anxiety are affecte d by captopril therapy after myocardial infarction in rats. Myocardial infarction was induced by ligation of the left coronary artery and ca ptopril therapy was started after 3 weeks. After 2 weeks of captopril therapy, anxiety-related behaviors were successively measured in four different tests: open field, elevated plus maze, home cage emergence, and open field escape. Myocardial infarction and captopril therapy aff ected behavior in the home cage emergence test and open field escape t est. On the basis of the data from the open field escape test, captopr il therapy appeared to decrease anxiety in infarcted rats and increase anxiety in sham rats. Because myocardial infarction and captopril the rapy did not affect anxiety-related behaviors in the open field and el evated plus maze tests, it is assumed that these interventions affect anxiety-related behaviors depending on the type of test. This was part ially supported by correlation analysis, which suggested that the beha vior of the rats in the different tests of anxiety may reflect differe nt anxiety-related traits.