Comparison of the effects of docosahexaenoic acid and palmitic acid on ischemia reperfusion injury using an isolated perfused rat heart.
MetadataShow full item record
Dietary docosahexaenoic acid (22:6n-3, DHA) has been shown to exert beneficial effects on coronary heart disease including the prevention of ischemia reperfusion injury. The ability to acutely infuse DHA to the heart to prevent ischemia reperfusion injury is a potentialy valuable tool in planned surgery where reperfusion and/or ischemia will take place including coronary artery bypass surgery and angioplasty. In the present study, hearts from chow-fed (AIN-93M) Sprague Dawley rats (male) 9-12 weeks of age were isolated and artificially perfused. The protocol included: 30 min stabilization period, 30 min global no flow ischemia, 15 min fatty acid infusion with reperfusion, and 75 min reperfusion in the absence of fatty acids. The fatty acid infusions included 10, 20, 40, 60, 80, 100 or 120 µM of either palmitate or DHA complexed to 3% essentially fatty acid free bovine serum albumin as well as a vehicle control. Heart functional data was recorded continuously and total heart infarct volume was determined after staining with triphenyltetrazolium chloride. DHA at 10µM significantly reduced the infarction area at the end of the reperfusion period compared to that observed in the10µM of palmitate and vehicle control conditions. Infarction areas after infusions with DHA or palmitate were similar to controls after 20-60 µM infusions and greater than controls after 80-120 µM infusions, except for the 100 µM palmitate conditions which were similar to the low and high doses. In this model of infusion, 120 µM of fatty acid was the maximum amount of DHA tolerated, as several hearts went into fibrillation and did not recover and failed to complete the reperfusion at concentrations greater than 120 µM of DHA. DHA and palmitate also exerted dose dependent effects on functional parameters. In summary, infusion of DHA and palmitate cause dose dependent effects on heart function.