The aim of this study is to evaluate liver toxicity on exposure to n-nitrosamine precursors as well
as the effect of ultraviolet light on n-nitrosamines  and its precursors. Toxicological evaluation of the liver
following single dose treatment of wistar rat with 8.2125 mg NaNO2
/adult rat and in rats given a combined dose of 50 mgDMA-HCl and 8.2125 mg NaNO 2
 /adult rat showed a steady elevation of the liver function enzymes.
Histopathological analysis of the liver showed hepatic  necrosis in the chemical induced rats. Following UV
exposure after in vitro  incubation of rat liver microsomal plus soluble fraction with NaNO2
 and NaNO2 plusDMA-HCl, nitrite concentration in the NaNO2
incubation medium was 19.5 and 2.2  : g/mL before and after UV exposure respectively while the nitrite concentration in the NaNO2
 plus DMA-HCl incubation medium was 23.5 and 2.5 : g/mL, respectively. Nitrite loss was significant  (p<0.05) between before and after UV exposure
in all groups. UV exposure, thus degraded the nitrosamine precursors, nitrite and DMA-HCl, thereby inhibiting
possible nitrosation. The high values of the activitie s of serum transaminases (AST and ALT), alkaline
phosphatases (ALP) and gamma-glutamyltransferses (( -GT), relative to control values are indicative of severe
intrahepatic cell damage.