| Abstract | Cilj istraživanja: Cilj je rada bio istražiti ulogu visokomasne hrane i derivata vitamina A, 13 cRA na metaboličke, upalne i adipogene parametre u ženki štakorica soja Lewis. Nacrt studije: Štakorice soja Lewis podijeljene su u 2 velike skupine, hranjene standardnom (STD) i visokomasnom (HFD), gdje 45 % od ukupne energije otpada na zasićene masti) hranom. Patofiziološke promjene izazvane su oralnom primjenom 13-cis retinoične kiseline (13 cRA) gastričnom kanilom u dozi od 7,5 mg/kg i 15 mg/kg tijekom 30 dana. Kontrolna skupina je obrađena suncokretovim uljem. Nakon 30-dnevne obrade, životinje su dodatnih 30 dana hranjene STD ili HFD hranom ad libitum prema protokolu te žrtvovane 60 dana. Materijal i metode: Tijekom pokusa praćena je tjelesna masa, a neposredno prije žrtvovanja, napravljen je oralni test tolerancije na glukozu (OGTT test). Prilikom žrtvovanja uzeti su uzorci krvi iz abdominalne aorte za hematološku i biokemijsku analizu, analizu lipidograma i aterogenih pokazatelja, koncentracije NO, arginaze i 12 proupalnih citokina, hormona leptina i adiponektina. Iz tkiva jetre i bubrega analizirani su parametri oksidacijskog stresa, a dio tkiva jetre poslužio je za histološku analizu i procjenu stupnja steatoze i fibroze dok je masno tkivo uzeto za procjenu adipoznog indeksa. Rezultati: Prehrana bogata mastima uz dodatak 13 cRA dovela je do povećanja tjelesne mase štakora, adipoznog indeksa, dislipidemije, hiperleptinemije, koncentracije VLDL-a, oksidativnog stresa jetre i bubrega, te aterogenih pokazatelja. Primjena 13 cRA u jedinki na STD nije dovela do promjena tjelesne mase tijekom 60-dnevnog tretmana, ali je dovela do blage promjene lipidograma, a dislipidemija je od ranije poznata nuspojava primjene retinoida. Zaključak: 13 cRA i HFD utječu na metaboličke parametre, metabolizam glukoze i lipida te njihova primjena ima različit utjecaj na metaboličke parametre u ovisnosti o primjeni STD ili HFD hrane. Rezultati doprinose rasvjetljavanju složene uloge derivata vitamina A u patogenezi pretilosti. Ostali se čimbenici, poput genetike, soja kojem je primijenjena terapija, starosti, spola, raspodjele masnog tkiva u organizmu također trebaju uzeti u obzir. |
| Abstract (english) | Study objective: The aim of this study was to determine the effect of high fat diet and 13 cRA, on metabolic, adipogenic and inflammatory parameters in female Lewis rats. Study design: Rats were divided into two groups: rats fed STD and fed HFD, where saturated fatty acids accounted for 45 % of total energy. There were three additional groups (6 rats per): two groups that received 13 cRA (7,5 mg/kg and 15 mg/kg) during a 30-day period and the control group that was given sunflower oil. Animals were sacrificed after 60 days. Material and methods: Body weight was monitored during the experiment. Shortly before the sacrifice, OGTT was performed. Venous blood sample was taken for haematological, biochemical analysis, levels of NO, arginase and proinflammatory cytokines, leptin and adiponectin, lipidogram and atherogenic parameters. Samples of liver and kidney tissue were taken for the analysis of oxidative stress parameters and liver tissue was also histologically analysed. Results: High fat diet with the 13 cRA supplementation resulted in increased weight gain, adiposity index, dyslipidaemia, hyperleptinaemia, VLDL concentrations, liver and kidney oxidative stress and atherogenic indices. Administration of 13 cRA in Lewis rats fed STD did not change the weight of the animals during the 60-day treatment, but it did lead to a slight change in lipidogram parameters. Here it should be noted that dyslipidaemia is an already known side effect of retinoid application. Conclusion: 13 cRA and HFD affect metabolic parameters, as well as glucose and lipid metabolism. Its administration has a different effect on metabolic parameters, depending on whether the STD or the HFD was applied. This study further clarified the complex role of vitamin A derivates in obesity pathogenesis. It is also important to consider other factors, such as genetics, particular strain which was given the therapy, age, sex, and adipose tissue distribution in the organism. |
