Cytochromes P450 and flavin monooxygenases - Targets and sources of nitricoxide

This article is a report on a symposium sponsored by the American Society f or Pharmacology and Experimental Therapeutics and held at the Experimental Biology 01 meeting in Orlando, FL. The presentations addressed the mechanis ms of inhibition and regulation of cytochrome P450 and flavin monooxygenase enzymes by nitric oxide. They also highlighted the consequences of these e ffects on metabolism of drugs and volatile amines as well as on important p hysiological parameters, such as control of blood pressure, renal ion trans port, and steroidogenesis. This is achieved via regulation of P450-dependen t prostacyclin, hydroxyeicosatetraenoic acid, and epoxyeicosatrienoic acid formation. Conversely, the mechanisms and relative importance of nitric oxi de synthases and P450 enzymes in NO production from endogenous and syntheti c substrates were also addressed.