Cyclo-oxygenase-2 inhibitors and the kidney: a case for caution.

Cyclo-oxygenase (COX) is one of the key enzymes in the biosynthesis of prostaglandins. Two isoforms of this enzyme COX-1 and COX-2 are known to exist. Among other functions, prostaglandins play an important role in the protection of the gastric mucosa and maintenance of renal function in pathophysiological conditions which would otherwise threaten it.