Early Functional Changes in Rat Arteries and Microcirculatory Vessels while Modeling Metabolic Syndrome

Early changes in the cardiovascular system of young Wistar rats were studied in modeling metabolic syndrome by a fructose load. It was found that despite some weight loss in rats fed a fructose diet, as compared to control animals, these animals showed the signs of metabolic syndrome: hyperglycemia, insulin resistance, dyslipidemia, increased activity of the sympathetic nervous system, arterial hypertension. Changes in the mesenteric arteries included an increase in the reactivity to phenylephrine and a decrease in acetylcholine-induced dilation due to decreased NO production by the endothelium, which is to a certain extent compensated by an increased production of the endothelium-derived hyperpolarizing factor realizing its effects through the activation of intermediate-conductance Ca 2+ -activated K + -channels. Fructose load led to the inhibition of soluble guanylate cyclase in arterial smooth muscle cells. In the skin microcirculatory bed of fructose-loaded rats, perfusion remained at the level typical for control animals, while skin microvessels showed an increase in neurogenic tone and an attenuation of endothelium-dependent tone. A decreased endothelial NO production was found in microcirculatory vessels, which was compensated by the synthesis of other endothelium-derived vasodilating factors.