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

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.