Cardiovascular disease remains the number one cause of death in America. Recent clinical and laboratory investigations suggest a protective role for omega-3 polyunsaturated fatty acids (fish oils) in cardiovascular disease. Numerous fish oil studies have demonstrated a reduction in blood pressure, serum lipids, platelet count and platelet aggregation. The marine oils or omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) appear to be the main components which can favorably alter these factors that may be associated with cardiovascular disease. Preliminary investigations have demonstrated relaxation responses to omega- 3 fatty acids, DHA and EPA in the isolated rat aorta. There are very little data available from the literature on the direct vascular effects of omega-3 fatty acids and no reports establishing the direct vascular effects of omega-3 fatty acids in the presence of cardiovascular risk factors. These risk factors include hypertension, age, cigarette smoking, and elevated levels of blood cholesterol. Therefore, the specific aims that will test the hypothesis that vascular relaxation induced by DHA and EPA way, in part, explain the protective and/or preventive role of omega-3 fatty acids in cardiovascular disease are to: define and compare the vascular effects of DHA and EPA on rat vascular tissue with increased age, determine the omega-3 fatty acids-induced vascular responses in rats fed a hyperlipidemia-inducing diet, examine the calcium-mediated vascular effects of DHA and EPA in normotensive rats, and compare the calcium-mediated vascular responses of omega-3 fatty acids in hypertensive rats. In vitro isolated bath perfusion of the thoracic aorta will be employed to assess changes in vascular tension. The vessels will be equilibrated for 60-90 minutes in Krebs-Ringer bicarbonate buffer solution under optimal tension. Isometric force will be measured and cumulative concentration- response curves to the omega-3 fatty acids will be generated. By determining the vascular effects of omega-3 fatty acids, a valid foundation for disease treatment, i.e. dietary modification can be developed. The proposed research will support and improve current nursing practice through the possible initiation of secondary and tertiary prevention strategies in cardiovascular disease.
