NADPH-diaphorase used to estimate alterations in the toxic rapeseed oil syndrome.

The evaluation of NADPH-diaphorase in the post-mitochondrial fraction of rat liver has been shown a sensitive method to estimate alterations of microsomal oxidase systems in acute and chronic intoxications. It is also useful to demonstrate the interaction of drugs with barbiturates, which normally induce this enzyme. To study the biochemical liver damage which may occur in the toxic rapeseed oil syndrome, we measured NADPH-diaphorase in the post-mitochondrial fraction of rats given oral doses of toxic rapeseed oil (1 ml/day for 6 days), or oleil or linoleil anilide (10 mg/kg for 6 days). One-half the rats were sacrificed at the end of the dosing period and the other half were killed 4 weeks later. In both circumstances one-half the rats were treated with 2 doses of 80 mg phenobarbital/kg. NADPH-diaphorase was strongly inhibited by toxic oil and fatty acid anilides (72-93%). Phenobarbital induction was completely depressed. Enzyme activity remained depressed after a 4-week latency period.