[The effect of the thyroid hormone triiodothyronine on the incorporation of 32P into brain phospholipids in rat and chicken (author's transl)].

The incorporation of 32P to brain phospholipids has been studied, in chicken as well as in rat. Both animal species were at different stage of brain development, although degrees of psychomotive development were identical. It is observed that the effect of triiodothyronine is more pronounced when the degree of brain myelination is smaller. The radioactive precursor is frequently incorporated to choline and ethanolamine phospholipids, and this incorporation is higher in hyperthyroid animals with a low degree of myelination. The triiodothyronine activates, in both animal species, the salvage pathway of phospholipid biosynthesis. This activation takes place 36 h before hormone action in chicken, while in rat, the most significant differences occur 36 h after hormone action.