The Action of C-Type Natriuretic Peptide on Apoptosis and P53 Expression in Human Cardiomyocytes

C-type natriuretic peptide (CNP) is endothelial cell origin and has potent vasodilatory and antimitogenic actions. We reported that CNP was markedly increased in human cardiac tissue with severe congestive heart failure. To date, the effects of CNP on cardiomyocyte growth and death remain unclear. Therefore, the present study was designed to investigate the actions of CNP on apoptosis and apoptosis-related gene p53 expression in human cardiomyocytes. Human cardiac atrial tissue was obtained from open-heart surgery (n=6). The cardiac tissue was minced and incubated in the special tissue culture system in the absence or presence of CNP (10 -7 M) for 24 hours. These studies were repeated with HS-142-1 (HS, 10 -6 M), a natriuretic peptide biological receptor antagonist. To detect the DNA fragmentation, in situ terminal deoxymucleotidyl transferase dUTP nick end labeling (TUNEL) was performed. The p53 expression was determined by immunohistochemical staining (IHCS). An average of 1000 nuclei was analyzed for TUNEL and p53 staining studies.