Effects of PNP and Arg exposure on histological observation of liver section. (A) Control+PBS group (CT) (B) Arg+PBS group (CTA) (C) Control+PNP group (PNP) (D) Arg+PNP group (PNPA). Liver sections of rats showed single arrow inflammatory infiltration, open arrow hepatic sinusoid damage, and filled arrow hepatic cells irregular arrangement scale bar=100 μm.