Metabolism of Natural and Synthetic Corticosteroids in Relation to their Effects on Mouse Fetuses

Abstract

¹⁴C-glucose uptake by mouse fetuses was reduced by doses of dexamethasone, 200 μg or more, which over 2 days caused fetal death. Uptake by strain C57B1/6J > A/J > SWV. Corticosterone or cortisol, 4 mg, caused neither reduced uptake nor fetal death. These differences occurred despite similar maternal hyperglycemia in all cases. Recovery of ³H-steroid after 15 min, total and unchanged steroid per gram fetal tissue was: corticosterone 1.7 and 0.3 %; dexamethasone 0.12 and 0.06 % of the dose. Rapid metabolism of corticosterone apparently prevents accumulation in fetal tissue sufficient to evoke a response under these conditions.