Taurine supplementation prevents endothelial dysfunction and attenuates structural changes in aortas from hypothalamic obese rats.

Abstract

Obesity predisposes to cardiovascular and metabolic diseases. The amino acid, L-taurine (Tau), regulates glucose and lipid homeostasis and vascular function. Here we investigated whether Tau supplementation prevents endothelial dysfunction in the thoracic aortas of monosodium glutamate-induced obese (MSG) rats. Male rats received subcutaneous injections of MSG (4mg/kg body weight/day) or saline (control group, CTL) during the first five days of life. From 21 to 150days of age, the rats were distributed into the groups: CTL, MSG, and CTL and MSG supplemented with 2.5% Tau in their drinking water (CTAU and MTAU). At 150-days old, MSG rats presented massive abdominal fat deposition, hypertriglyceridemia, hyperinsulinemia, glucose intolerance and high plasma levels of malondialdehyde (MDA), a lipid peroxidation marker. Tau supplementation attenuated fat accumulation in perigonadal adipose tissue and prevented the increase in triglycerides and MDA plasma levels. Aortic rings of MSG rats presented reduced vasodilation in response to acetylcholine (ACh). No modifications in insulin-induced vasodilatation, or Akt and eNOS phosphorylation, were observed in MSG aortas; thoracic aortas from MSG rats presented reduced tunica media thickness, with a lower aortic wall thickness/lumen diameter ratio and decreased total collagen content. Tau supplementation restored ACh-induced vasodilation and collagen content. Our study presents the first evidence that Tau prevents disruptions in vascular reactivity and in extracellular matrix composition in thoracic aortas of MSG-obese rats. The vascular protective actions of Tau may be linked to reduced lipid peroxidation and a reduction in cardiovascular risk factors, such as abdominal fat and hypertriglyceridemia.