C-type natriuretic peptide immunoreactivity in human breast vascular endothelial cells.

The present study was undertaken to determine the presence of CNP immunoreactivity in human breast tissue (n = 9). Immunohistochemical staining of breast tissue revealed the presence of CNP immunoreactivity localized to vascular endothelial cells. This study demonstrates for the first time that CNP immunoreactivity is present in humans. Based upon the knows biological actions of CNP, these findings suggest that CNP may function as part of an endothelium-derived vasoregulatory system.