Abstract

The sulfhydryl reagents iodoacetic acid, iodoacetamide, p-chloromercuribenzoate and N-ethylmaleimide were capable of inhibiting norepinephrine-stimulated lipolysis in isolated adipose cells. In addition, iodoacetamide inhibited lipolysis stimulated by theophylline and by dibutyryl cyclic adenosine monophosphate. The data indicate a probable intracellular site of action, possibly upon a triglyceride lipase. The dithiol dimercaprol was capable of preventing the inhibitory action of the compounds but could not reverse established inhibition. The monothiol mercaptoethanol could prevent the inhibition of N-ethylmaleimide. Elucidation of the ultimate mechanism of inhibition by these compounds awaits isolation of the entire system for lipase activation from adipose tissue.