Proposed mechanisms for red palm oil induced cardioprotection in a model of hyperlipidaemia in the rat.
High-cholesterol diets alter myocardial and vascular NO-cGMP signaling and have been implicated in ischaemic/reperfusion injury. We investigated the effects of dietary red palm oil (RPO) containing fatty acids, carotonoids, tocopherols and tocotrienols on myocardial ischaemic tolerance and NO-cGMP pathway function in the rat. Wistar rats were fed a standard rat chow+/-RPO, or a standard rat chow+cholesterol+/-RPO diet. Myocardial mechanical function and NO-cGMP signaling pathway intermediates were determined before, during and after 25 min ischaemia. RPO-supplementation improved aortic output recovery and increased myocardial ischaemic cGMP concentrations. Simulated ischaemia (hypoxia) increased cardiomyocyte nitric oxide levels in the two RPO supplemented groups, but not in control non-supplemented groups. RPO supplementation also increased hypoxic nitric oxide levels in the control diet fed, but not the cholesterol fed rats. These data suggest that dietary RPO may improve myocardial ischaemic tolerance by increasing bioavailability of NO and improving NO-cGMP signaling in the heart.
Esterhuyse
Johan S
JS
Faculty of Health and Wellness Sciences, Cape Peninsula University of Technology, Cape Town, South Africa.
van Rooyen
Jacques
J
Strijdom
Hans
H
Bester
Dirk
D
du Toit
Eugene F
EF
D000818:Animals; D002316:Cardiotonic Agents / Q000008:administration & dosage*; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D006152:Cyclic GMP / Q000032:analysis / Q000378:metabolism; D004042:Dietary Fats, Unsaturated / Q000008:administration & dosage*; D004195:Disease Models, Animal; D006949:Hyperlipidemias / Q000378:metabolism*; D066298:In Vitro Techniques; D008054:Lipid Peroxides / Q000032:analysis / Q000378:metabolism; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000378:metabolism / Q000517:prevention & control*; D032383:Myocytes, Cardiac / Q000737:chemistry; D009569:Nitric Oxide / Q000032:analysis / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000378:metabolism; D000073878:Palm Oil; D010938:Plant Oils / Q000008:administration & dosage*; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000187:drug effects; D013482:Superoxide Dismutase / Q000032:analysis / Q000378:metabolism
D002316:Cardiotonic Agents; D002791:Cholesterol, Dietary; D004042:Dietary Fats, Unsaturated; D008054:Lipid Peroxides; D010938:Plant Oils; D009569:Nitric Oxide; D000073878:Palm Oil; D019001:Nitric Oxide Synthase; D013482:Superoxide Dismutase; D006152:Cyclic GMP