OBJECTIVE

We analyzed the structural, mechanical, myogenic and functional properties of resistance arteries of ApoE KO compared to wild type (WT) mice. We also determined the influence of saturated fat in comparison to virgin olive oil-enriched diets in vascular wall abnormalities.

METHODS

Male ApoE KO (ApoE) and WT mice (8-weeks-old) were assigned to the groups: standard chow diet (SD), high fat diet (HFD), virgin olive oil (VOO) and high polyphenol-VOO-enriched diet (Oleaster(®)) (OT) (15% w/w). After 20 weeks, structural, mechanical and myogenic properties of isolated small mesenteric arteries (SMA) were analyzed by pressure myography. For functional studies, vasodilatation to acetylcholine was assessed. Arterial superoxide anion production was measured by ethidium fluorescence.

RESULTS

Hypertrophic remodeling and distensibility in ApoE KO SMA was lower compared to WT mice, suggesting an alteration in the autoregulation mechanisms aimed to compensate disease progression. However, ApoE deficiency resulted in a lower impairment in myogenic tone in response to intraluminal pressure, in addition to an improved endothelium-dependent hyperpolarizing vasodilatation. Also, we evidenced the beneficial effects of VOO in contrast to a saturated fat-enriched diet on SMA wall disorders. Only the endothelial function improvement induced by olive oil was dependent on polyphenols content.

CONCLUSION

Resistance arteries structure, mechanic, myogenic and functional responses from ApoE KO mice significantly differ from WT mice, evidencing the influence of the type of diet on these disorders. These results are particularly useful to determine the contribution of resistance arteries during the atherosclerotic process and to provide novel insights into the Mediterranean dietary pattern to reduce the burden of atherosclerotic disease.