“Inhibitors of microsomal monooxygenase such as SKF 525A, metyrapone , nicotinamide, and carbon monoxide inhibited the hydroxylation of PGA , and PGE,; similarly cytochrome c and antibodies to NADPH-cytochrome c reductase inhibited these reactions, indicating that the hydroxylation of these prostaglandins is catalyzed by a typical monooxygenase system.”