The influence of carbon tetrachloride on nitrosamine induced hepatocarcinogenesis in rats

In a chronic toxicity conducted for a period of 165 days, rats were divided into four treatment groups. Group I served as untreated controls. Group II was treated with weekly oral dose of carbontetrachloride (CCl₄) @ 0.5ml/kg bw in olive oil at 1:1 ratio. Group III received diethylnitrosamine(DENA) @ 10 mg/kg bw by gastric intubation weekly. Group IV received weekly oral dose of DENA @ (10mg/kg bw) followed bt CCl₄ @ 0.5 ml/kg bw after 3 days interval. In CCl₄ treated rats, lipid peroxidation (LPO) and gamma glutamyl transpeptidase (GGT) activities in liver were increased compared to that of controls, which coincided with hepatotoxic lesions pathologically. In DENA treated rats, a decline in LPO level and increase in GGT activity in comparison to that of control liver was observed biochemically. Grossly,the liver was enlarged, tumified with multiple pin head sized raised greyish white areas and histologically, clear cell foci and eosinophilic foci were appreciated which developed into nodules and hepatomas at 165 days. In DENA followed by CCl₄ treatment,similar biochemical changes as that of DENA group was observed and pathologically the onset of preneoplastic and neoplastic lesions were advanced by 30 days when compared to DENA treatment alone.