Early alterations in vascular contractility associated to changes in fatty acid composition and oxidative stress markers in perivascular adipose tissue.
OBJECTIVE
To test the early effect of fructose-induced changes in fatty acid composition and oxidative stress markers in perivascular adipose tissue (PVAT) upon vascular contractility.


METHODS
Adult male Wistar rats were fed a commercial diet without (CD) or with 10% fructose (FRD) in the drinking water for 3 weeks. We measured plasma metabolic parameters, lipid composition and oxidative stress markers in aortic PVAT. Vascular contractility was measured in aortic rings sequentially, stimulated with serotonin (5-HT) and high K+-induced depolarization using intact and thereafter PVAT-deprived rings.


RESULTS
Comparable body weights were recorded in both groups. FRD rats had increased plasma triglyceride and fructosamine levels. Their PVAT had an increased saturated to mono- or poly-unsaturated fatty acid ratio, a significant decrease in total superoxide dismutase and glutathione peroxidase activities and in the total content of glutathione. Conversely, lipid peroxidation (TBARS), nitric oxide content, and gluthathione reductase activity were significantly higher, indicating an increase in oxidative stress. In aortic rings, removal of PVAT increased serotonin-induced contractions, but the effect was significantly lower in rings from FRD rats. This effect was no longer observed when the two contractions were performed in PVAT-deprived rings. PVAT did not affect the contractions triggered by high K+-induced depolarization either in CD or FRD rats.


CONCLUSIONS
FRD induces multiple metabolic and endocrine systemic alterations which also alter PVAT and the vascular relaxant properties of this tissue. The changes in PVAT would affect its paracrine modulation of vascular function.
GINFIV - Grupo de Investigación en Fisiología Vascular, Grupo Vinculado a CENEXA (UNLP - CONICET LA PLATA), Facultad de Ciencias Exactas, Universidad Nacional de La Plata, La Plata, Argentina. ar@biol.unlp.edu.ar
Alejandro
A
Rebolledo
Oscar R
OR
Rebolledo
Carlos A
CA
Marra
María E
ME
García
Ana R
AR
Roldán Palomo
Laura
L
Rimorini
Juan J
JJ
Gagliardino
D050153:Abdominal Fat / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology*; D001835:Body Weight / Q000502:physiology; D004435:Eating / Q000502:physiology; D005227:Fatty Acids / Q000378:metabolism*; D005632:Fructose / Q000494:pharmacology; D005979:Glutathione Peroxidase / Q000378:metabolism; D007333:Insulin Resistance / Q000502:physiology; D008297:Male; D023421:Models, Animal; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012701:Serotonin / Q000494:pharmacology; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014661:Vasoconstriction / Q000187:drug effects / Q000502:physiology*
D005227:Fatty Acids; D017392:Thiobarbituric Acid Reactive Substances; D005632:Fructose; D009569:Nitric Oxide; D012701:Serotonin; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase