title: Time-dependent supplementation of vitamin E influences leptin expression in the aortic layers of rats fed atherogenic diet.
abstract: An excessive consumption of a diet rich in saturated fatty acids is a key factor in pathogenesis of cardiovascular diseases which are strictly connected with leptin imbalance in the vessels. However, whether vitamin E supplementation would influence leptin expression in aortic layers is still unknown. For 3 or 6 weeks male Wistar rats were fed a high-fat (20% w/w) diet with lard as dietary fat source with or without vitamin E supplementation (50 mg/100 g of diet). The 6-week intake of an atherogenic diet increased total cholesterol (TC) and high density lipoprotein cholesterol (HDL) plasma levels simultaneously lowering TC/HDL ratio (ANOVA p≤0.0001 for all three parameters). After longer period of feeding it was stated that leptin expression in all three aortic layers was enhanced (ANOVA p≤0.0001 for endothelium, tunica media and adventitia, respectively) with decreased leptin plasma concentration (ANOVA p≤0.0001). After both periods of feeding vitamin E supplementation caused an increase in plasma HDL content and a decrease of TC/HDL ratio. In the 3-week experiment vitamin E addition caused a decrease in leptin plasma levels (Fisher's test, 3L versus 3LE: p≤0.002) and an increase in leptin expression in all three aortic layers (Fisher's test, 3L versus 3LE p≤0.005, p≤0.01 and p≤0.05 respectively for endothelium, tunica media and adventitia). The contradictory results were observed in the 6-week experiment in which vitamin supplementation decreased leptin expression in the aortic endothelium (Fisher's test, 6L versus 6LE: p≤0.001) with lack of changes in the other two layers of the aorta and plasma. The study showed that vitamin E supplementation influenced leptin expression in aortic layers in rats fed atherogenic diet differently depending on the length of feeding period. It may suggest that vitamin E consumption plays an important role in the control of leptin status in the endothelium.
authors.affiliation: Laboratory of Molecular Biology, The Kielanowski Institute of Animal Physiology and Nutrition, Polish Academy of Sciences, Jablonna, Poland. agata_krawczynska@wp.pl.
authors.forename: A
authors.initials: A
authors.lastname: Krawczynska
authors.forename: E
authors.initials: E
authors.lastname: Olczak
authors.forename: A
authors.initials: A
authors.lastname: Rembiszewska
authors.forename: A P
authors.initials: AP
authors.lastname: Herman
authors.forename: J
authors.initials: J
authors.lastname: Gromadzka-Ostrowska
mesh_terms: D063194:Adventitia / Q000378:metabolism; D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage*; D001011:Aorta / Q000187:drug effects* / Q000378:metabolism; D059305:Diet, High-Fat / Q000009:adverse effects*; D019587:Dietary Supplements; D004334:Drug Administration Schedule; D004730:Endothelium, Vascular / Q000378:metabolism; D020738:Leptin / Q000097:blood / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D017540:Tunica Media / Q000378:metabolism; D014810:Vitamin E / Q000008:administration & dosage*
chemical_list: D000975:Antioxidants; D020738:Leptin; D014810:Vitamin E