Prostaglandins: Biphasic Dose Responses

Biphasic dose responses induced by prostaglandins are documented and assessed with respect to quantitative features of their dose-response functions, mechanistic foundation, and biological generalizability. Biphasic responses were seen for multiple endpoints, including DNA synthesis, neutrophil migration, corticoster-one production, fibroblast proliferation, and other parameters. In addition, numerous nonsteroidal antiinflamma-tory agents and other drugs alter prostaglandin concentrations and or transport in a biphasic dose- response manner. These findings have considerable implications for the understanding of basic biological regulatory processes as well as clinical practices.