Blood glutathione and cysteine changes in cardiovascular disease

The need to investigate aminothiols such as glutathione (GSH), cysteine (Cy s), and homocysteine (Hcy) in blood is stimulated by the current interest i n hyperhomocysteinemia as a risk factor for atherosclerosis, Our current go al was to determine whether various cardiovascular (CV) diseases altered le vels of GSH and Cys in blood and the relationships between these two thiols . Blood samples from 96 patients with atherosclerosis and other CV diseases were analyzed and compared with those from 33 control subjects. In CV pati ents, GSH levels were normal, but free plasma Cys was significantly higher (P < .0001), In patients with atherosclerosis, bound plasma Cys was 21% hig her than that in control subjects (P < .0001), and in patients with other C V diseases it was 14% higher (P = .023), Also, in patients with CV diseases , correlations of free GSH with free Cys (P < .007) and total GSH and Cys w ith age (P < .04) differed from that in control subjects. There were no dif ferences related to functional disability or duration of disease. A key fin ding was that these abnormal levels of plasma Cys occurred in both atherosc lerotic and non-atherosclerotic CV diseases. These results indicate that hi gh levels of oxidized and bound Cys in CV patients create an oxidative envi ronment that may increase susceptibility to vascular damage.