Genetic expression of endothelial nitric oxide synthase in human atrial myocardium.

ABSTRACT

OBJECTIVE: To investigate the expression of endothelial nitric oxide synthase (eNOS) in human cardiac tissues. DESIGN: We attempted to determine the genetic expression and localization of eNOS in normal human atrial tissue. MATERIAL AND METHODS: In normal human right atrial tissues from five donors during cardiac transplantation, eNOS expression and localization were assessed by using Northern blot analysis, in situ hybridization, and immunohistochemical staining. RESULTS: Northern blot analysis and in situ hybridization demonstrated that eNOS messenger RNA is present in cardiomyocytes. Positive immunohistochemical staining was observed in the cytoplasm of cardiomyocytes. CONCLUSION: These studies show for the first time the genetic expression and distribution of eNOS in human atrial myocardium and suggest that the eNOS mediated paracrine and autocrine pathway may participate in the control of myocardial function in humans.