On the impact of NO-globin interactions in the cardiovascular system

During the last years, many reports have provided evidence that the concept of a simple, diffusion-controlled action of NO must be extended by the existence of storage and long-distance transport forms of NO suitable to extend the half-life of the NO radical. In addition, hemoglobin (myoglobin)-dependent formation of NO may account for an additional NO source in the vasculature and in red muscle. On the other hand, there is increasing evidence that the specific subcellular localization of NO synthase isoforms is a critical determinant for their proper biological function. However, it remains obscure how a localized mode of NO action may occur without effective barriers that prevent the diffusion of NO released at a specific site within a cell to other compartments. Members of the globin family of proteins, mainly hemoglobin and myoglobin, have been found to play important roles in all of these processes.