tokens: Liver injuries were quantified as serum activities of glutamate - oxaloacetate transaminase ( GOT ) and glutamate - pyruvate transaminase ( GPT ). While AAP caused a 117 - fold elevation of serum transaminase activities in mice kept on a standard laboratory diet , which was significantly exacerbated by ethanol and inhibited by nicotinic acid amide ( NAA ), adverse effects were noted in animals fed a diet free of precursors of NAD .