Effect of thyroid hormones on the 3-oxo acid CoA-transferase activity in rat brain during development.

The changes in the developmental pattern of 3-oxo acid CoA-transferase activity in the brain of hypothyroid rats and the effect of triiodothyronine on this enzyme activity have been investigated. Hypothyroid rats showed lower activity than controls during the suckling period. However, higher enzyme levels were found in treated rats after weaning in contrast to control animals. The results suggest that thyroid hormones promote the development of enzymes of ketone-body metabolism in the brain.