Effect of dietary eicosapentaenoic acid on plasma lipids and platelet function in stroke-prone spontaneously hypertensive rat.

An investigation was undertaken to study the effect of EPA in rats fed different protein sources. A highly concentrated EPA (78% EPA, ethyl ester form), manufactured from sardine oil was administered to SHRSP (Stroke-prone spontaneously hypertensive rat) and WKY (Wistar Kyoto) for 4 weeks. Casein or SPI (soy protein isolate) was used as protein source in the experimental diet. In the experiment concerning casein diet, showing significant decrease in systolic blood pressure, plasma lipids of SHRSP were observed after EPA treatment, but no significant difference was found in SPI diet group. Although there was no significant change in systolic blood pressure of WKY after EPA treatment, a similar effect of EPA on plasma lipids level and platelet aggregation were also observed in WKY. However, supplementing methionine to SPI diet induced the reducing effect of EPA in rats. In addition, higher level ratios of EPA to arachidonic acid were observed in the plasma and platelets of rats fed SPI diet containing methionine supplement when compared with rats fed SPI diet. It was suggested that the amino acid profile was related to the effective utilization of EPA in rats.