Neonatal hypothyroidism and early undernutrition in the rat: defective maturation of structural membrane components in the central nervous system.

The action of neonatal hypothyroidism and early undernutrition on the lipid and protein composition, as well as, on the activity of 2'3' cyclic nucleotide 3' phosphohydrolase was studied in different subcellular fractions isolated from 20 day old hypothyroid and undernourished rats. Based on protein content, a marked decrease (70%) in the recovery of myelin was observed in both experimental conditions. The lipid composition of myelin in both groups was, however, different; while cholesterol, total phospholipids, and total galactolipids decreased in a similar fashion in the two situations; sulfatides and plasmalogens were much more affected in hypothyroid rats.