The metabolism of 7-ethoxycoumarin in primary maintenance cultures of adult rat hepatocytes.

7-Ethoxycoumarin is metabolized to 7-hydroxycoumarin in short-term (1-4 days) maintenance cultures of adult rat hepatocytes. The 7-hydroxycoumarin is predominantly found as the sulphate and glucuronic acid conjugates. This pattern of metabolism is very similar to that observed with freshly-isolated rat hepatocytes and suggests that the culture system may be of value in studying the metabolism of novel chemicals designed for human therapeutic use. The specific activity of microsomal monooxygenase activity falls by 50-60% during 4 days in culture. This is not reflected by the sulphate and glucuronic acid conjugation pathways which are retained at normal levels throughout the entire 4-day culture period.