Cardiac taurine and principal amino acids in right and left ventricles of patients with either aortic valve stenosis or coronary artery disease: the importance of diabetes and gender

Abstract

Free intracellular taurine and principal α-amino acids (glutamate, glutamine, aspartate, asparagine and alanine) are abundant in human heart. They are cellular regulators and their concentration can change in response to disease and cardiac insults and have been shown to differ between hypertrophic left ventricle (LV) and the relatively "normal" right ventricle (RV) in patients with aortic valve stenosis (AVS). This difference has not been shown for coronary artery disease (CAD) and there are no studies that have simultaneously compared amino acid content in LV and RV from different pathologies. In this study we investigated the effect of disease on taurine and principal amino acids in both LV and RV, measured in myocardial biopsies collected from patients with either AVS (n = 22) or CAD (n = 36). Amino acids were extracted and measured using HPLC. Intra-and inter-group analysis was performed as well as subgroup analysis focusing on gender in AVS and type 2 diabetes in CAD. LV of both groups has significantly higher levels of taurine compared to RV. This difference disappears in both diabetic CAD patients and in male AVS patients. Alanine was the only α-amino acid to be altered by diabetes. LV of female AVS patients had significantly more glutamate, aspartate and asparagine than corresponding RV, whilst no difference was seen between LV and RV in males. LV of females has higher glutamate and glutamine and less metabolic stress than LV of males. This work shows that in contrast to LV, RV responds differently to disease which can be modulated by gender and diabetes.

Taurine and cardiac disease: state of the art and perspectives

“…Also, low plasma levels of taurine have been reported in patients with diabetic cardiomyopathy (Franconi et al 1995(Franconi et al , 2004. It has also been reported by Lewis et al (2014) that the increase in metabolic stress induces a decrease in myocardial taurine. Such cardiac metabolic stress leads to the development of necrosis, hypertrophy, and heart failure.…”

“…The beneficial effects of taurine have been demonstrated in many diseases such as decreased serum low-density lipoprotein, decreased progression of atherosclerosis, and protection against ischemiareperfusion injury of the myocardium (Schaffer and Kim 2018;Xu et al 2008;Abebe and Mozaffari 2011;Lambert et al 2015;De Luca et al 2015). Besides, the beneficial effects of taurine in diabetic cardiovascular complications are well documented (Franconi et al 1995(Franconi et al , 2004Inam-U-Llah et al 2018;Lewis et al 2014;Manna et al 2013;Tappia et al 2011Tappia et al , 2013Tappia et al , 2018Turan 2010). It has been suggested that taurine increases the high-energy phosphate content of the heart (Schaffer and Kim 2018;Schaffer et al 2016).…”

Amino Acid Imbalance in Atherosclerosis

“…Studies on the determination of taurine and a number of amino acids predominant in the myocardium (glutamate, aspartate, glutamine and asparagine) in coronary insufficiency showed their differences in the content in the left and right ventricles in coronary insufficiency. A comparison of the levels of these amino acids in aortic stenosis and coronary heart disease in myocardial biopsy specimens showed higher concentrations of taurine in the left ventricle in both situations [34]. With severe, progressive cardio sclerosis in the rabbit myocardium, the content of phenylalanine and tyrosine increased, which was also found in patients with coronary heart disease, and the degree of increase in the level of amino acids changed depending on the clinical forms of coronary atherosclerosis (angina pectoris of various functional classes, myocardial infarction).…”

“…It takes an active part in the metabolism of carbohydrates, fats and amino acids, the activation of antioxidant and detoxifying systems. Methionine serves as an essential precursor of cysteine, glutathione, and taurine and, as a cysteine precursor, is involved in the synthesis of insulin and coenzyme A. Methylation processes (involving S -adenosylmethionine) are associated with gene expression, the functioning of the sympathoadrenal system, and the formation of choline and acetylcholine [34].…”

Amino Acid Imbalance in Atherosclerosis

“…It takes an active part in the metabolism of carbohydrates, fats and amino acids, the activation of antioxidant and detoxifying systems. Methionine serves as an essential precursor of cysteine, glutathione, taurine and, as a cysteine precursor, is involved in the synthesis of insulin and coenzyme A. Methylation processes (involving Sadenosylmethionine) are associated with gene expression, the functioning of the sympathoadrenal system, and the formation of choline and acetylcholine [34].…”