The field of study of natriuretic peptides becomes more complex as we enter the second decade since their discovery. The attractive hypothesis that a single peptide secreted by the atria could regulate the physiological responses to salt and water loading has proven simplistic. Rather the atrial natriuretic peptide story has opened the door on a whole family of peptides, secreted from the atria, the ventricles, the brain, and even the kidney itself, all working in concert to achieve this regulation. The regulation of renal function by natriuretic peptides is presumably the result of the integration of these different peptides effects. Thus while atrial derived NP circulates and has direct effects on the glomerulus, other sources of NP (such as the kidney) may be responsible for some of the tubular effects of NP. Further definition of the mechanisms of regulation of the kidney derived NP are needed before any further conclusions can be drawn.