Inhibition of prostaglandin synthesis in rabbit kidney medulla slices by antioxidants.

The inhibitory effects of NN'-diphenyl-p-phenylenediamine (DPPD), sodium diethyldithiocarbamate (SDDC) and 2,6-di-t-butylphenol (DTBP) on the generation of medullary prostaglandin E have been compared. DPPD (1 microM) and SDDC (1 mM) failed to inhibit arachidonic acid-induced stimulation of prostaglandin E synthesis, while DTBP (1 mM) inhibited it. This suggests that DPPD and SDDC inhibit prostaglandin formation by affecting a phospholipase pathway, and the inhibition of prostaglandin generation by DTBP occurs at the cyclooxygenase step.