A major complication that can limited the evolution of a cardiac transplantation over the long term is the development of accelerated coronary arteriosclerosis. This form of coronary disease is different from the atherosclerotic coronary disease of patients not submitted to cardiac transplantation. Current evidence obtained by intravascular ultrasound, has demonstrated that the occurrence of a precocious endothelial dysfunction, mainly mediated by the inducible isoform of the nitric oxide synthase (iNOS) expression, is associated with the development of atherosclerosis in cardiac allografts during the first year of the transplant. This review was developed starting with basic concepts (description of the enzyme and its known isoforms; a brief comparison between them), reviewing the coronary endothelial dysfunction after cardiac transplantation, from the specific point of view of the NOS enzymatic function. In cardiac transplantation iNOS promotes acute rejection but prevents chronic episodes. The relationship between these opposing effects remains unknown we only know that they are different mechanisms which are time-dependent.
Nitro-oxide synthese; Endothelium; Endothelium; Heart transplantation; Graft rejection
