Taurine Attenuates Acute Hyperglycaemia-Induced Endothelial Cell Apoptosis, Leucocyte-Endothelial Cell Interactions and Cardiac Dysfunction

Abstract

Objectives: Hyperglycaemia is implicated in microvascular inflammatory injury and subsequent cardiac injury/dysfunction. Leucocyte adhesion to the endothelium, migration into tissue and toxic metabolite release are early critical steps. Taurine is a semi-essential amino acid that is endothelial protective and restrains excess leucocyte activity by the formation of less toxic inflammatory mediators. The aim was to establish if taurine reduces acute hyperglycaemia-induced endothelial cell apoptosis and leucocyte interactions and associated cardiac abnormalities. Methods: Male Sprague-Dawley rats (190–250 g) were randomised to control, hyperglycaemia, and hyperglycaemia plus taurine pre-treated groups. Taurine was gavaged (200 mg/kg body weight) for 5 days. Intravenous hyperglycaemia was established which was 4 times that of baseline for the 3-hour experiment. Using intravital microscopy, mesenteric post-capillary venules were examined for leucocyte rolling, adhesion and migration every 30 min from baseline. Endothelial cell apoptosis and intracellular adhesion molecule (ICAM-1) expression were assessed. In a separate experiment, blood pressure, pulse rate, cardiac injury marker (troponin T), cardiac tissue injury and oedema were also assessed. Results: Hyperglycaemia significantly increased leucocyte adhesion and migration. Blood pressure and troponin T were also elevated significantly. Taurine prevented these cardiac changes, endothelial cell apoptosis and ICAM-1 expression. Conclusions: Taurine may have a therapeutic role in reducing diabetic microvascular inflammatory injury and concomitant cardiac dysfunction.

Taurine Attenuates Multiple Organ Injury Induced by Intestinal Ischemia Reperfusion in Rats

“…It has been shown that taurine attenuates acute hyperglycemia-induced apoptosis of endothelial cells [39]. The present study has also demonstrated that taurine reduced cellular apoptosis of multiple organs induced by II/R.…”

Effects of taurine on the reactivity of aortas from diabetic rats

“…However, co-incubation of aortas with 5-10 mM taurine concentration-dependently prevented both the hyperglycemiainduced alterations in vascular smooth muscle contractility and endothelium-mediated vasorelaxation, the effects being more pronounced at higher concentrations. Although a protective effect of taurine against toxicity caused by hyperglycemia in endothelial cells has been reported (Wu et al, 1999;Casey et al, 2007), the present observation is the first of its kind regarding the effect of the nutrient on intact vascular preparation. Further demonstrating the significance of these data, hyperglycemiainduced hypertension in rats has been shown to be normalized with in vivo treatment with taurine, while blood pressure of control animals was not altered by the nutrient (Casey et al, 2007).…”

Protective effect of taurine on diabetic rat endothelial dysfunction

“…The expression of intracellular adhesion molecule-1 (ICAM-1), which mediates cell-cell adhesion, was decreased by taurine in Sprague-Dawley rats with impaired ROS scavenging capability. Taurine given intravenously at 200 mg/kg for 5 days before the induction of inflammation prevented a significant increase in the expression of ICAM-1 in the post-capillary venules (high endothelial cell region) (6). The production of tumor necrosis factor-α (TNF-α), an important pro-inflammatory cytokine, has been shown to be down-regulated through a multitude of mechanisms including substrate depletion and uncoupling of eNOS (24).…”