Estrogen may prevent depression after heart attack
Estrogen may protect against heart failure (HF)-related depression by preventing the creation of inflammation-causing chemicals in the brain, according to research published in the American Journal of Physiology.
“These results suggest that estrogens prevent depression-like behavior induced by HF post myocardial infarction (MI) in young adult female rats by inhibiting pro-inflammatory cytokines production and actions in the prefrontal cortex,” the researchers, led by Frans H.H. Leenen, MD, PhD, of the University of Ottawa in Canada, wrote.
The researchers studied a rat model of heart failure after MI, which was induced by occlusion of the left anterior descending artery in young adult male and female rats and in adult female rats without ovaries. Half the rats without ovaries received estrogen supplements. Rats who did not exhibit HF were used as controls and were matched with rats of their same gender in the study group.
Researchers tested depression by giving the animals tests that measured learning, memory and the ability to experience pleasure. They also took blood samples to measure inflammation levels in the brain. They found:
- Male rats with heart failure exhibited signs of depression and brain inflammation compared to the male rat control group.
- Female rats without ovaries exhibited higher rates of depression-like behavior than all of the males.
- The estrogen receiving female rats showed no depression and there was no increase in inflammation in brain areas involved in mood and pleasure.
“Our findings demonstrate that sex and estrogens influence neuroinflammation and depression-like behavior in rats with heart failure post heart attack,” the researchers said in a prepared statement. “Understanding the mechanisms contributing to these sex-specific and estrogen-dependent responses may contribute to new therapies that may be sex-specific.”