Book of Abstracts - New Frontiers 2022

Abstracts of poster presentations

METABOLIC SYNDROME IN HYPERTRIACYLGLYCEROLEMIC RATS: EFFECTS OF ANTIOXIDANTS

Z. Brnoliakova, V. Knezl, R. Sotnikova, Z. Gasparova

Institute of Experimental Pharmacology and Toxicology, Center of Experimental Medicine, Slovak Academy of Sciences, Bratislava, Slovakia

Long-lasting disturbances in lipid and glucose metabolism present in metabolic syndrome (MetS) lead to serious cardiovascular diseases. Inflammation and oxidative stress are closely related to MetS, therefore agents possessing both anti-inflammatory and anti-oxidative properties should have the potential in regulating MetS. The study was aimed to evaluate the effect of vitamin E (VitE) on basal biochemical and physiological parameters characterizing MetS and on the changed function of the heart and the aorta. Furthermore, the possible potentiation of VitE effect by synthetic antioxidant SMe1EC2 (SMe) was also tested. MetS was induced in hereditary hypertriacylglycerolemic rats (HTG) by the 5 weeks administration of a high-fat diet (1% cholesterol, 7,5% pork lard) with additional 10% fructose (HFFD). Controls were fed a standard diet (SD). VitE (100mg/kg/daily) alone or in combination with SMe (15mg/kg/daily) was administered p.o. After 5 weeks, rats were killed and biochemical analyses, as well as functional studies on the heart and the aorta, were performed. The biochemical parameters assessed in serum by ELISA methods: total cholesterol (TC), low-density lipoproteins (LDL), high-density lipoproteins (HDL), triacylglycerols (TG), thiobarbituric acid reactive substances (TBARs), N-acetyl glucosaminidase (NAGA) and blood glucose (Glu), as well as the oral glucose tolerance test (oGTT) were performed. The physiological status of rats was monitored (weight gain, diet consumption). The functional state of the aorta was tested in vitro under isometric conditions as endothelial-dependent relaxation of the phenylephrine-precontracted preparations by acetylcholine. The heart function was tested using Langendorff preparation (under constant pressure). The functional parameters of isolated heart, dysrhythmias and evoked fibrillations were evaluated in conditions of ischemia-reperfusion. The HFFD diet increased the body weight gain and serum levels of TC and LDL. A tendency towards the increase of serum NAGA was found. The endothelial function of the aorta was disturbed. The HFFD diet significantly increased the heart flow and the force of contraction, compared to SD. The evoked fibrillation was not influenced by HFFD. The HFFD caused a decreased number of serious dysrhythmias (ventricular tachycardia-VT; ventricular fibrillation-VF) while the number of ventricular premature beats (VPB) was increased. The fortification of the HFFD diet with VitE, either alone or in combination with SMe, decreased body weight gain, depressed blood pressure, improved particular biochemical parameters, and ameliorated endothelium-dependent relaxation. The combination of VitE and SMe also suppressed the occurrence of serious dysrhythmias VT and VF. Our data indicate that the HFFD diet-related disturbances led to alterations within pathophysiology in HTG rats. The results showed that a combination of antioxidants might have the potential to amend disorders accompanying MetS.

Keywords: metabolic syndrome, HTG rats, vitamin E, SMe1EC2, Langendorff preparation

Funding: The work was supported by grants: VEGA No 2/0120/19, VEGA No 2/0104/21, APVV 18-0336, and EU project ITMS 2014+ 313021Y920.

74