Arachidonic acid metabolism by rat liver cells (the C-9 cell

Rat liver cells (the C-9 cell line) are capable of producing, from endogenously liberated arachidonic acid, prostaglandins 12, E2 and F2,,. Greater than 95 % of these cyclooxygenase products is prostaglandin 12. Arachidonic acid metabolism is stimulated by treatment of the C-9 cells with epidermal growth factor, vaso-pressin, angiotensin II or thrombin. Stimulation by combined treatments with vasopressin, angiotensin II or thrombin is addi-tive; but each stimulation, when incubated in the presence of epidermal growth factor, is synergistic. These stimulations are dependent on Ca. They are inhibited by indomethacin and dexamethasone. The cells exhibit homologous, but not heterol-ogous, desensitization to vasopressin and thrombin. The syner-gistic stimulation by epidermal growth factor and vasopressin is inhibited by prior treatment of the cells with epidermal growt