The effects of dietary evening primrose, black currant, borage and fungal oils on plasma, hepatic and vascular tissue fatty acid composition in the spontaneously hypertensive rat

Hypertension is associated with alterations in the metabolism of ω-6 polyunsaturated fatty acids (PUFA) in tissues. Compositional changes in tissue fatty acids may affect cellular properties such as ion permeability and receptor interactions important to blood pressure regulation. Recent evidence suggests that the ω-6 PUFA, gamma-linolenic acid (GLA), is a potent blood pressure lowering nutrient. In this study, the effects of dietary oils enriched with GLA (evening primrose, black currant, borage and fungal) on plasma, hepatic and vascular tissue fatty acid composition were determined in spontaneously hypertensive rats. The oils increased the composition of GLA and dihomogamma-linolenic acid in hepatic, aortic and renal arterial tissue (p<0.05). Arachidonic acid levels were also increased in the liver (p<0.05). The data suggest that alterations in the fatty acid profiles of hepatic and vascular tissue induced by GLA-enriched oils may be responsible for the favorable blood pressure lowering effect of GLA.