Two cyclooxygenase isozymes, COX-1 and -2, are known to catalyze the rate-limiting step of prostaglandin synthesis and are the targets of nonsteroidal anti-inflammatory drugs. Recently, the presence of a variant of COX-1, named COX-3, has been demonstrated that is especially sensitive to acetaminophen and strongly expressed in brain tissue. The proposed study will examine prostanoid suppression in the periphery by inhibition of COX-1, -2, and -3, and evaluate the time course of expression of COX isoenzymes in terms of level of mRNA and protein itself.