Combined toxic effects of tetracycline and ethinyl estradiol on liver function of mice.

The combined effects of ethinyl estradiol (EE) (0.5 micrograms/g s.c. once daily for 4 days) and tetracycline (TC) or doxycycline (DC) (50 micrograms/g i.v.) on liver weight and water content, serum transaminases, alkaline phosphatase, urea, triglycerides, and cholesterol as parameters of various liver functions were investigated in mice. It became apparent that depending on the parameter tested synergistic and antagonistic effects may occur, e.g., synergistic effects were observed with the serum transaminases and liver cholesterol; antagonistic effects were seen with the serum urea and serum cholesterol.