While metabolic syndrome is often associated with obesity, 25% of humans suffering from it are not obese and the effect of physical activity remains unclear in such cases. Therefore, we used hereditary hypertriaclyglycerolemic (HHTg) rats as a unique model for studying the effect of spontaneous physical activity [voluntary running (VR)] on metabolic syndrome-related disorders, such as dyslipidemia, in non-obese subjects. Adult HHTg males were fed standard (CD) or high-sucrose (HSD) diets ad libitum for four weeks. Within both dietary groups, some of the rats had free access to a running wheel (CD+VR, HSD+VR), whereas the controls (CD, HSD) had no possibility of extra physical activity. At the end of the four weeks, we measured the effects of VR on various metabolic syndrome-associated parameters: (i) biochemical parameters, (ii) the content and composition of triacylglycerols (TAG), diacylglycerols (DAG), ceramides and membrane phospholipids, and (iii) substrate utilization in brown adipose tissue. In both dietary groups, VR led to various positive effects: reduced epididymal and perirenal fat depots; increased epididymal adipose tissue lipolysis; decreased amounts of serum TAG, non-esterified fatty acids and insulin; a higher insulin sensitivity index. While tissue ceramide content was not affected, decreased TAG accumulation resulted in reduced and modified liver, heart and skeletal muscle DAG. VR also had a beneficial effect on muscle membrane phospholipid composition. In addition, compared with the CD group, the CD+VR rats exhibited increased fatty acid oxidation and protein content in brown adipose tissue. Our results confirm that physical activity in a non-obese model of severe dyslipidemia has many beneficial effects and can even counteract the negative effects of sucrose consumption. Furthermore, they suggest that the mechanism by which these effects are modulated involves a combination of several positive changes in lipid metabolism.

• MeSH
• Running physiology   MeSH
• Adipose Tissue, White pathology   MeSH
• Cell Membrane metabolism   MeSH
• Ceramides metabolism   MeSH
• Phospholipids metabolism   MeSH
• Adipose Tissue, Brown metabolism   pathology   MeSH
• Hypertriglyceridemia blood   MeSH
• Muscle, Skeletal metabolism   pathology   MeSH
• Rats MeSH
• Metabolic Syndrome blood   MeSH
• Lipid Metabolism * MeSH
• Oxidative Stress MeSH
• Muscle Cells metabolism   MeSH
• Triglycerides metabolism   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Ceramides MeSH
• Phospholipids MeSH
• Triglycerides MeSH

The plasma profile of major lipoprotein classes and its subdivision into particular fractions plays a crucial role in the pathogenesis of atherosclerosis and is a major predictor of coronary artery disease. Our aim was to identify genomic determinants of triglyceride and cholesterol distribution into lipoprotein fractions and lipoprotein particle sizes in the recombinant inbred rat set PXO, in which alleles of two rat models of the metabolic syndrome (SHR and PD inbred strains) segregate together with those from Brown Norway rat strain. Adult male rats of 15 PXO strains (n = 8-13/strain) and two progenitor strains SHR-Lx (n = 13) and BXH2/Cub (n = 18) were subjected to one-week of high-sucrose diet feeding. We performed association analyses of triglyceride (TG) and cholesterol (C) concentrations in 20 lipoprotein fractions and the size of major classes of lipoprotein particles utilizing 704 polymorphic microsatellite markers, the genome-wide significance was validated by 2,000 permutations per trait. Subsequent in silico focusing of the identified quantitative trait loci was completed using a map of over 20,000 single nucleotide polymorphisms. In most of the phenotypes we identified substantial gradient among the strains (e.g. VLDL-TG from 5.6 to 66.7 mg/dl). We have identified 14 loci (encompassing 1 to 65 genes) on rat chromosomes 3, 4, 7, 8, 11 and 12 showing suggestive or significant association to one or more of the studied traits. PXO strains carrying the SHR allele displayed significantly higher values of the linked traits except for LDL-TG and adiposity index. Cholesterol concentrations in large, medium and very small LDL particles were significantly associated to a haplotype block spanning part of a single gene, low density lipoprotein receptor-related protein 1B (Lrp1b). Using genome-wide association we have identified new genetic determinants of triglyceride and cholesterol distribution into lipoprotein fractions in the recombinant inbred panel of rat model strains.

• MeSH
• Genome-Wide Association Study MeSH
• Cholesterol chemistry   MeSH
• Species Specificity MeSH
• Genomics * MeSH
• Polymorphism, Single Nucleotide MeSH
• Rats MeSH
• Lipoproteins chemistry   MeSH
• Triglycerides chemistry   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Cholesterol MeSH
• Lipoproteins MeSH
• Triglycerides MeSH

Aims. To determine the effect of two different diets (high-sucrose (HS) and high-fat (HF)) on the main metabolic pathways potentially contributing to the development of steatosis: (1) activity of the liver lysosomal and heparin-releasable lipases; (2) fatty acid (FFA) oxidation; (3) FFA synthesis de novo; (4) VLDL output in vivo in a rat model of metabolic syndrome (MetS), hereditary hypertriglyceridemic (HHTg) rats fed HS or HF diets. Results. Both diets resulted in triacylglycerol (TAG) accumulation in the liver (HF > HS). The intracellular TAG lipolysis by lysosomal lipase was increased in both groups and positively correlated with the liver TAG content. Diet type significantly affected partitioning of intracellular TAG-derived fatty acids among FFA-utilizing metabolic pathways as HS feeding accentuated VLDL secretion and downregulated FFA oxidation while the HF diet had an entirely opposite effect. FFA de novo synthesis from glucose was significantly enhanced in the HS group (fed ≫ fasted) while being completely eradicated in the HF group. Conclusions. We found that in rats prone to the development of MetS associated diseases dietary-induced steatosis is not simply a result of impaired TAG degradation but that it depends on other mechanisms (elevated FFA synthesis or attenuated VLDL secretion) that are specific according to diet composition.

• Publication type
• Journal Article MeSH

This work focused on the effect of Maca on lipid, anti-oxidative, and glucose parameters in hereditary hypertriglyceridemic (HHTg) rat. Maca (1%) was administred to rats as a part of a high-sucrose diet (HSD) for 2 weeks. Rosiglitazone (0.02%) was used as a positive control. Maca significantly decreased the levels of VLDL (very low density lipoproteins), LDL (low density lipoproteins), and total cholesterol, and also the level of TAG (triacylglycerols) in the plasma, VLDL, and liver. Maca, as well as rosiglitazone, significantly improved glucose tolerance, as the decrease of AUC (area under the curve) of glucose showed, and lowered levels of glucose in blood. The activity of SOD (superoxide dismutase) in the liver, the GPX (glutathione peroxidase) in the blood, and the level of GSH (glutathione) in liver increased in all cases significantly. Results demonstrate that maca seems to be promising for a positive influence on chronic human diseases (characterized by atherogenous lipoprotein profile, aggravated antioxidative status, and impaired glucose tolerance), and their prevention.

• MeSH
• Antioxidants pharmacology   MeSH
• Cholesterol blood   MeSH
• Glucose metabolism   MeSH
• Glutathione metabolism   MeSH
• Glutathione Peroxidase metabolism   MeSH
• Hyperlipoproteinemia Type IV drug therapy   metabolism   MeSH
• Liver enzymology   metabolism   MeSH
• Rats MeSH
• Thiobarbituric Acid Reactive Substances analysis   MeSH
• Cholesterol, LDL blood   MeSH
• Lepidium chemistry   MeSH
• Lipid Metabolism drug effects   MeSH
• Carbohydrate Metabolism drug effects   MeSH
• Area Under Curve MeSH
• Rats, Wistar MeSH
• Plant Extracts pharmacology   MeSH
• Superoxide Dismutase metabolism   MeSH
• Triglycerides blood   MeSH
• Cholesterol, VLDL blood   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antioxidants MeSH
• Cholesterol MeSH
• Glucose MeSH
• Glutathione MeSH
• Glutathione Peroxidase MeSH
• Thiobarbituric Acid Reactive Substances MeSH
• Cholesterol, LDL MeSH
• Plant Extracts MeSH
• Superoxide Dismutase MeSH
• Triglycerides MeSH
• Cholesterol, VLDL MeSH

Two inbred rat strains, differing in their resistance to the induction of myocardial lesions by the administration of isoprenaline (ISO), have been developed. The extent of ISO-induced myocardial lesions (IML) was three to five times lower in the ISO-resistant (IR) strain as compared to that in the ISO-sensitive (IS) strain. The two strains differ also in a number of other genetically determined features, e.g., a higher myocardial glycogen content (MGC) and higher adipose tissue weight in IR rats. Between IML extent and MGC a significant negative correlation has been demonstrated in 2nd filial generation of IR and IS hybrids. By contrast, no correlation has been found between the resistance to the development of IML and the other genetically determined features studied. High resistance to the development of IML and a high MGC were also noted in another inbred strain, the hypertriacylglycerolemic (HTG) rats. Comparison of IML extent in HTG, IR and IS rats has revealed that the extent of IML, while depending on MGC, is independent of triacylglycerolemia. MGC can be raised in IR and IS rats by various interventions (e.g., repeated administration of ISD or fasting). Regardless of the intervention used, it entails a simultaneous increase in resistance to the development of IML. In vivo administration of glucose and insulin, however, exerts only a minimal effect on MGC and on the extent of IML. It may be concluded, therefore, that under our experimental conditions the enhanced resistance to the development of IML, whether genetically determined (IR, HTG rats) or induced by some interventions (fasting, repeated ISO administration), is closely related to an increased MGC.

• MeSH
• Adrenergic beta-Agonists toxicity   MeSH
• Glycogen metabolism   MeSH
• Rats, Inbred Strains MeSH
• Isoproterenol toxicity   MeSH
• Rats MeSH
• Myocardium metabolism   MeSH
• Heart drug effects   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Male MeSH
• Female MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Comparative Study MeSH
• Names of Substances
• Adrenergic beta-Agonists MeSH
• Glycogen MeSH
• Isoproterenol MeSH