Nejvíce citovaný článek - PubMed ID 18936763
Long-term pioglitazone treatment enhances lipolysis in rat adipose tissue
Background: Hypertriglyceridemia has serious health risks such as cardiovascular disease, type 2 diabetes mellitus, nephropathy, and others. Fenofibrate is an effective hypolipidemic drug, but its benefits for ameliorating disorders associated with hypertriglyceridemia failed to be proven in clinical trials. Methods: To search for possible causes of this situation and possibilities of their favorable influence, we tested the effect of FF monotherapy and the combination of fenofibrate with silymarin on metabolic disorders in a unique model of hereditary hypertriglyceridemic rats (HHTg). Results: Fenofibrate treatment (100 mg/kg BW/day for four weeks) significantly decreased serum levels of triglyceride, (-77%) and free fatty acids (-29%), the hepatic accumulation of triglycerides, and the expression of genes encoding transcription factors involved in lipid metabolism (Srebf2, Nr1h4. Rxrα, and Slco1a1). In contrast, the hypertriglyceridemia-induced ectopic storage of lipids in muscles, the heart, and kidneys reduced glucose utilization in muscles and was not affected. In addition, fenofibrate reduced the activity of the antioxidant system, including Nrf2 expression (-35%) and increased lipoperoxidation in the liver and, to a lesser extent, in the kidneys and heart. Adding silymarin (micronized form, 600 mg/kg BW/day) to fenofibrate therapy increased the synthesis of glycogen in muscles, (+36%) and reduced hyperinsulinemia (-34%). In the liver, it increased the activity of the antioxidant system, including PON-1 activity and Nrf2 expression, and reduced the formation of lipoperoxides. The beneficial effect of combination therapy on the parameters of oxidative stress and lipoperoxidation was also observed, to a lesser extent, in the heart and kidneys. Conclusions: Our results suggest the potential beneficial use of the combination of FF with SLM in the treatment of hypertriglyceridemia-induced metabolic disorders.
- Klíčová slova
- fenofibrate, glycogen synthesis, insulin resistance, metabolic syndrome, oxidative stress, reesterification of fatty acids, silymarin, triglycerides,
- Publikační typ
- časopisecké články MeSH
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
- běh fyziologie MeSH
- bílá tuková tkáň patologie MeSH
- buněčná membrána metabolismus MeSH
- ceramidy metabolismus MeSH
- fosfolipidy metabolismus MeSH
- hnědá tuková tkáň metabolismus patologie MeSH
- hypertriglyceridemie krev MeSH
- kosterní svaly metabolismus patologie MeSH
- krysa rodu Rattus MeSH
- metabolický syndrom krev MeSH
- metabolismus lipidů * MeSH
- oxidační stres MeSH
- svalové buňky metabolismus MeSH
- triglyceridy metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- ceramidy MeSH
- fosfolipidy MeSH
- triglyceridy MeSH
Metabolic interactions between adipose tissue and the heart may play an active role in progression of heart failure (HF). The aim of the study was to examine changes in myocardial and adipose tissue metabolism and gene expression in a rat HF model induced by chronic volume overload. HF was induced by volume overload from aorto-caval fistula (ACF) in 3-month-old male Wistar rats and animals were studied in the phase of decompensated HF (22nd week). HF rats showed marked eccentric cardiac hypertrophy, pulmonary congestion, increased LV end-diastolic pressure, and intraabdominal fat depletion. HF rats had preserved glucose tolerance, but increased circulating free fatty acids (FFA) and attenuated insulin response during oral glucose challenge. Isolated organ studies showed preserved responsiveness of adipose tissue lipolysis and lipogenesis to epinephrine and insulin in ACF. The heart of HF animals had markedly reduced triglyceride content (almost to half of controls), attenuated anti-oxidative reserve (GSH/GSSG), upregulated HF markers (ANP, periostin, thrombospondin-4), specific signaling pathways (Wnt, TGF-β), and downregulated enzymes of mitochondrial fatty acid oxidation, citric acid cycle, and respiratory chain. Adipose tissue transcription profiling showed upregulated receptor for gastric inhibitory polypeptide. In conclusion, ACF-induced HF model displays several deregulations of systemic metabolism. Despite elevation of systemic FFAs, myocardial triglycerides are low and insulin levels are attenuated, arguing against a role of lipotoxicity or insulin resistance in this model. Attenuated postprandial insulin response and relative lack of its antilipolytic effects may facilitate intraabdominal fat depletion observed in ACF-HF animals.
- MeSH
- aorta chirurgie MeSH
- arteriovenózní píštěl MeSH
- arteriovenózní zkrat MeSH
- biologické markery metabolismus MeSH
- epididymis metabolismus patologie MeSH
- glukózový toleranční test MeSH
- glutathion metabolismus MeSH
- hemodynamika MeSH
- inzulin krev MeSH
- játra patologie MeSH
- kardiomyocyty metabolismus patologie MeSH
- krysa rodu Rattus MeSH
- kyseliny mastné neesterifikované krev MeSH
- látky reagující s kyselinou thiobarbiturovou metabolismus MeSH
- ledviny patologie MeSH
- metabolismus lipidů MeSH
- myokard metabolismus patologie MeSH
- oxidační stres MeSH
- plíce patologie MeSH
- potkani Wistar MeSH
- remodelace komor MeSH
- srdce patofyziologie MeSH
- srdeční selhání metabolismus patologie patofyziologie MeSH
- stanovení celkové genové exprese MeSH
- superoxiddismutasa metabolismus MeSH
- tuková tkáň metabolismus patologie MeSH
- velikost orgánu MeSH
- venae cavae chirurgie MeSH
- zvířata MeSH
- Check Tag
- krysa rodu Rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Názvy látek
- biologické markery MeSH
- glutathion MeSH
- inzulin MeSH
- kyseliny mastné neesterifikované MeSH
- látky reagující s kyselinou thiobarbiturovou MeSH
- superoxiddismutasa MeSH