Effects of perilla oil on the key gene expression regulating hepatic VLDL synthesis in obese rats / 中国实验动物学报

Objective This study aims to investigate the effects of high-fat diet rich in perilla oil on the expression of key genes that regulate hepatic VLDL synthesis in obese rats .Methods Sixty healthy male 5-week old SD rats were randomly divided into 2 groups.The rats in the normal control group (NC, n=12) were given normal diet, and the rats in the high fat group ( HF, n=48) were given a pure high fat diet in order to induce rat models of obesity .In the intervention period, the obesity model rats were randomly divided into 4 subgroups including consistent high fat group (CHF) and three intervention groups depending on perilla oil substitution rate of lard in CHF:20%PO, 50%PO and 100%PO.The serum triglyceride (TG) of the rats was measured after 4 weeks.Real-time PCR was applied to measure microsomal triglyceride transfer protein ( Mtp) and apolipoprotein B ( Apob) mRNA, and western blot assay was used for detecting the expression of MTP and APOB in the liver .Results Compared with the NC group , the CHF rats exhibited significantly high fat deposi-tion.The serum TG was markedly higher and the MTP and APOB were decreased at gene and protein levels in the CHF group compared with the NC group .After the intervention , PO remarkably reduced the level of serum TG and decreased he-patic fat deposition as it showed by pathological examination .At the gene and protein levels , MTP and APOB were upregu-lated by PO to different degrees .Conclusions All the three PO intervention can promote VLDL synthesis and secretion , and decrease the hepatic fat deposition in the obese rats .Furthermore , PO upregulates the expression of MTP at gene and protein levels in a dose-dependent manner .

Differential scanning calorimetric studies of native and freeze-damaged very low density lipoproteins in hen's egg yolk plasma.

Lipid thermal transition patterns of the very low density lipoproteins in native and variously treated egg yolk plasma and extracted total very low density lipoproteins lipids have been recorded by differential scanning calorimetry in the temperature range 220–300 K, after lowering the freeze endotherm of free water in the sample with ethylene glycol. Three distinguishable patterns of lipid endotherms, designated types 1, 2 and 3 were obtained, respectively, from (i) native very low density lipoproteins in egg yolk plasma, (ii) freeze damaged very low density lipoproteins in gelled egg yolk plasma and (iii) extracted total lipids of very low density lipoproteins dispersed in water. Protein-depleted 'lipid core' particles of very low density lipoproteins obtained by exhaustive proteolysis of egg yolk plasma gave type 2 lipid transition pattern suggesting similarities in its lipid association with that of the freeze damaged very low density lipoproteins. Freezing the 'lipid cores' of very low density lipoproteins led to phase separation and gave type 3 lipid transition pattern of water-dispersed, phase-separated total very low density lipoprotein lipids. Relative heat uptake of native very low density lipoproteins in egg yolk plasma was about 15% lower than the freeze damaged sample or of the extracted total lipids. Treatments which prevented aggregation and gelation of very low density lipoproteins in egg yolk plasma during frozen storage, namely with additives such as glycerol or NaCl, gave subsequent lipid transition pattern intermediate between type 1 and 2, indicating that while very low density lipoprotein aggregation is prevented, additives do not altogether prevent changes in lipid association in these particles.