Derangement of Basic Amino Acids and Nitric Oxide Levels in Patients Undergoing Cardiothoracic Surgery

Background: a cyclic relationship exists, between; arginine, citrulline, and ornithine. arginase is a specific enzyme that plays a role in this relationship. these basic amino acids have a role in the induction of nitric oxide (no) and as anti-inflammatory and antioxidant. this study aimed to elucidate the role of surgical injuries and anesthesia on plasma levels of the above-mentioned amino acids and no and to determine whether the changes in these levels can be correlated to the duration of surgery and anesthesia exposure.materials and methods: the study included: group a (41 patients) who underwent coronary bypasses and group b (17 patients) who underwent lung cancer surgery. an amino acid analyzer was used for the detection of amino acids, while no was estimated by a spectrophotometric method.results: the study revealed a significant decrease in the intra-operative levels of arginine, citrulline, ornithine, and no compared to their pre-operative levels in both groups.conclusion: depletion of these basic amino acids is possibly multifunctional and can be associated with an increase in arginase, surgical trauma, anesthesia, and stress.