Dietary n-3 PUFAs affect the blood pressure rise and the cardiac function modulation in a hyperinsulinemia rat model<em> in vivo</em>

Abstract

National audienceThis study was designed to assess in vivo the cardiovascular consequences of a dietary docosahexaenoic (DHA) or eicosapentaenoic (EPA) acid specific intake in a hyperinsulinemia (HI) model presented by fructose-induced insulin-resistant rats. Wistar rat (n=6 in each dietary group of control or HI rats) were fed for two months a diet containing 62% fructose, and supplemented (or not for control, NFD) with either DHA or EPA (240 mg per day). Modifications of the cardiovascular parameters (rise in blood pressure (BP), heart rate (HR), modulation, ECG) were continously monitored using an intra-abdominal implanted telemetry system in HI rats. The myocardial phospolipid fatty acid profile was significantly affected by DHA intake, less by EPA intake. The individual linear regressions over the experiment indicate a reduced increase in HR and BP, in both HI rats receiving DHA or EPA as compared to NFD HI rats, without affecting the HI and hypertriglyceridemia induced by the fructose died. Using the tail sphygnomanometric method, the BP appared again significantly lover in both DHA and EPA group than in the NFD group but unchanged in the non insulin resistant rats, whatever the died considered. The HR was significantly reduced in the HI-DHA group that also exhibited after analysis of ECG a shorter QT interval, as compared to the 2 other dietary HI groups. Both purifed n-3 PUFAs, EPA and DHA, were efficient to prevent the HI-induced rise of BP even it not effect on glucose metabolism was observed; and that DHA exhibited a double effect directly exerted on the heart (adrenergic system maybe