Irreversible protein binding of acrylonitrile

Abstract

1. After i.p. injection of [2,3-¹⁴C]acrylonitrile to rats, a significant portion of radioactivity becomes irreversibly attached to proteins of liver, lung, spleen and other tissues.

2. When rat liver microsomes were incubated with [2,3-¹⁴C]acrylonitrile, a time-dependent irreversible binding of radioactivity occurred to microsomal proteins. This binding was not dependent on NADPH. A high extent of binding to heat-inactivated microsomes indicated that no enzymic metabolic step was involved.

3. The irreversible binding of [2,3-¹⁴C]acrylonitrile to rat liver microsomal protein in vitro was inhibited by thiols (cysteine, glutathione, mcrcaptoethanol). The greatest inhibitory potency was displayed by dithiocarb (diethyl dithiocarbamate).