RESUMEN
Considering that sex related differences in cardiac response to flaxseed (FSO) and evening primrose oil (EPO) are insufficiently known present investigation assessed the effect of these two oils, on the cardiac function of isolated rat hearts and the possible role of sex in this. The present study was carried out on 60 adult male Wistar albino rats randomly divided into 6 groups: male rats treated with EPO, dose of 10 mg/kg/day; female rats treated with EPO, dose of 10 mg/kg/day; male rats treated with FSO, dose of 300 mg/kg/day; female rats treated with FSO, dose of 300 mg/kg/day; control group of female rats treated with regular laboratory diet for animals; control group of male rats treated with regular laboratory diet for animals. Using the Langendorff technique, markers of the heart function were evaluated: the maximum and minimum rates of pressure development in the left ventricle (LV; dP/dtmax, dP/dtmin), systolic and diastolic left ventricular pressure (SLVP, DLVP, respectively), heart rate (HR) and coronary flow (CF). Male rats treated with EPO had significantly higher (p = 0.016) mean values of dP/dtmax, dP/dtmin, SLVP and DLVP (average increase for all CPPs 20%, 25%, 30% and 110%, respectively), compared to the group of male rats treated with FSO (p = 0.914). Our study results indicate that both types of PUFA oils only slightly changed the function of the isolated rat heart in male but not in female rats. Nevertheless, the difference between oil treatments was found in male rats who had stronger cardiac response after supplementation with EPO.