Effect Of N-3 Polyunsaturated Fatty Acids On Lipids And Bone Metabolism Of The Simulated Weightlessness Rats

Objective:Cardiovascular disease and osteoporosis have been the leading causes of death in human. Recently epidemiologic research has found that the abnormity of lipid metabolism has a tight relationship with bone metabolism. As tail-suspended rats model can form an abnormal model of lipid metabolism as well as bone metabolism, We added three levels offish oil to the diets of rats of this model to determine the effects of n-3 polyunsaturated fatty acids on lipid and bone metabolism, so as to determine the interaction of these two chronic diseases and clarify the mechanism of these diseases. Methods:49 male Sprague-Dawley rats were divided into five groups: tail-suspension group I, fed with10 wt % corn oil, tail-suspension groups IK III, IV fed with three levels of fish oil (0.5, 1.5 or 3.0 wt %; low, middle and high level offish oil, respectively) , normal gravity group V fed with 10 wt % corn011 served as normal control. The experimental term was 30 days. Results:Viscoelasticity of cell membrane in group III was significantly higher than that of group I(p<0.01); Vascular endothelial cells were less in group II compared to group I; Serum total cholesterol and triglyceride, Serum lipoprotein were lower in groups II compared to group I, the higher fish oil content in diet, the lower serum lipid concentration in micro-gravity groups. Peak load of fracture femur has significant increase in group II compared to group I (p<0.01) . The higher fish oil content in diet, the lower serum Ca . Serum osteocalcin in group III approached to group V. IGF-I decreased significantly in group I compared with group V (p<0.01), TNF- a in group I increased significantly compared with group V (p<0.01), and in group III these factors had no significant difference with group V.Conclusion:Dietary n-3 Polyunsaturated fatty acid had distinguished benefit effects on lipid and bone metabolism of the tail-suspended model, thus had certain effects on the prevention of cardiovascular disease and osteoporosis. It can be inferred that n-3 PUFA balance the metabolism by modifying the cytokines effects, eicosanoid biosynthesis and cell differentiation.