Resolvin D1 decreases caspase-3 activation in the limbic system after myocardial infarction

Myocardial infarction (MI) induces an inflammatory process that is associated with increased apoptosis in the limbic system of rats and the development of post-MI depressive symptoms. Resolvin D1 (RvD1), an omega-3 fatty acid metabolite, is known for its pro-resolution properties; it reduces infarct size and attenuates post-MI depression-like symptoms. The present study was designed to determine if a single RvD1 dose could abate caspase-3 activation, a marker of apoptosis, in the limbic system. Male Sprague-Dawley rats underwent 40 min of myocardial ischemia, followed by 24-h reperfusion. Five min before MI, the animals received a single intra-cardiac RvD1 injection (0.01, 0.1 or 0.3 μg) or vehicle (saline). Infarct size was assessed and caspase-3 activity measured in the amygdala and hippocampus. Rats receiving 0.1 or 0.3 μg RvD1 showed significantly decreased infarct size. Caspase-3 activity was significantly attenuated in the lateral amygdala and dentate gyrus with 0.1 μg RvD1 and in the CA1 region of the hippocampus and medial amygdala with 0.3 μg RvD1. In conclusion, RvD1 could reduce infarct size and caspase-3 activity in the amygdala and hippocampus.