EPIDERMAL GROWTH-FACTOR AND GLUCOCORTICOID EFFECTS ON BLOOD PROSTAGLANDIN E(2) LEVEL IN DENA-INDUCED CARCINOGENESIS

This paper describes results on carcinogenesis in rats induced with di ethylnitrosamine (DENA; 280 mg/kg single dose, i.p.). After inducing c hemical carcinogenesis, the animals were treated with different compou nds that affect cell proliferation and the effects on the blood prosta glandin E(2) (PGE(2)) levels were observed. These compounds were epide rmal growth factor (EGF, 10 mu g/kg/24 h i.p., 7 days) and dexamethaso ne (4 mg/kg/24 h i.p., 7 days). The blood PGE(2) levels of rats were m easured by RIA (Radioimmunoassay). The blood PGE(2) levels increased s ignificantly following DENA and EGF administrations alone or together. Dexamethasone administration decreased the blood PGE(2) levels. In co nclusion the data show that the increase in the plasma PGE(2) level by DENA treatment was enhanced by EGF but opposed by dexamethasone. This suggests that EGF may be effective as a promoter in chemical carcinog enesis.