Epidermal growth factor and glucocorticoid effects on blood prostaglandin E2 level in DENA-induced carcinogenesis

This paper describes results on carcinogenesis in rats induced with diethylnitrosamine (DENA; 280 mg/kg single dose, i.p.). After inducing chemical carcinogenesis, the animals were treated with different compounds that affect cell proliferation and the effects on the blood prostaglandin E2 (PGE2) levels were observed. These compounds were epidermal growth factor (EGF, 10 micrograms/kg/24 h i.p., 7 days) and dexamethasone (4 mg/kg/24 h i.p., 7 days). The blood PGE2 levels of rats were measured by RIA (Radioimmunoassay). The blood PGE2 levels increased significantly following DENA and EGF administrations alone or together. Dexamethasone administration decreased the blood PGE2 levels. In conclusion the data show that the increase in the plasma PGE2 level by DENA treatment was enhanced by EGF but opposed by dexamethasone. This suggests that EGF may be effective as a promoter in chemical carcinogenesis.