Volume status as a determinant of the influence of renal PGE on renal function

Although prostaglandins and their precursors are ubiquitous in the body, the kidney is one of the most active sites of synthesis. Despite extensive studies, the precise influence of the renal prostaglandins on renal hemodynamics and renal sodium handling remains unsettled. While the vasoactive properties of infused prostaglandins and their precursors on renal blood flow have been demonstrated repeatedly in both man and a number of animal species, the physiologic role of these agents on renal blood flow regulation is not established. Although the precise mechanism(s) are incompletely defined, clinical observations collectively suggest that the caveat of primum non nocere must be invoked in the use of nonsteroidal antiinflammatory drugs in patients with disease states characterized by a diminished effective volume. Teleologically, heightened renal prostaglandin synthesis may be perceived as an important part of the renal adaptive mechanism in such volume-contracted states. Inhibition of these crucial prostaglandin functions may eventuate in excessive salt and water retention and acute renal insufficiency.