Free nitric oxide in spent capd fluid: A leap of faith?

Since the phenomenon of endothelium-dependent relaxation was described in the early 1980s, and the subsequent identification of nitric oxide (NO) as the biological mediator of this process, interest in NO has spiraled out of the cardiovascular field into almost all areas of biology. In humans and other vertebrates, NO has now been demonstrated to play important key roles in neurotransmission and immunological and inflammatory responses. Moreover, evidence would suggest that the NO signaling pathway is spread throughout the entire phylogenetic scale, where it is involved in such diverse functions as visual and tactile learning in the cephalopod Octopus vulgaris and blood sucking in the Trypanosomiasis “kissing bug” vector Rhodnius prolixus. In addition, the emerging picture in plants is that NO functions as a ubiquitous signal involved in various physiological processes that include germination, root growth, stomatal closing, and adaptive response to various stresses.