ENZYMATIC DEGRADATION OF DIAZINON BY RAT LIVER MICROSOMES

A method was developed to study the in vitro metabolism of diazinon by rat liver preparations. Preliminary results showed that diazinon is rapidly degraded into diethyl phosphorothioic and diethyl phosphoric acids by a rat liver microsomal enzyme system requiring NADPH and oxygen. These findings and the inhibition by carbon monoxide strongly suggest the involvement of cytochrome P450, the carbon monoxide binding pigment. The enzyme system is found to be more active in Tris buffer than in phosphate buffer. Oxidative degradation appears to be the major route of metabolism of diazinon. © 1969.