[Measurement of prostaglandin E2 content in lung tissue of mouse]

A radioimmunoassay (RIA) was applied for the determination of PGE2 levels in the lung from 4 groups of male ICR mice 1) fed a standard diet, 2) fed a 20% corn oil-supplemented diet (HFD) for 2 weeks, 3) given a single s.c. injection of 15 mg/kg of 4NQO, a potent lung carcinogen and 4) given a s.c. injection of 4NQO and subsequently fed HFD for 2 weeks. Animals were sacrificed at week 3, and the lung was carefully excised and frozen in liquid nitrogen to prevent the postmortem synthesis of PGE2. PGE2, extracted from the lung tissue, was purified and then measured with or without adding a known amount of PGE2. The lung levels of PGE2 were shown to be significantly higher in the groups treated with HFD and/or 4NQO than the group fed a standard diet. These results show that the modified RIA method can be used for the measurement of PGE2 contents in the tissue of animals.