28: Effects of early postnatal undernutrition on rat CNS myelin proteins and glycoprotsins

Fisher rats were undernourished from the first postnatal day to 20 days of age by maintaining 15 pups with each mother. Control animals came from 5 pups litters. Body and brain weights from 30-day-old undernourished rats were reduced to 66% and 86% respectively, of control values. Myelin was purified from undernourished and control animals at 15, 20, 30 and 60 days of age. The amounts of myelin isolated per gram fresh brain were decreased in undernourished animals during starvation and after a long recovery period. Myelin protein composition was not different in undernourished or control rats. The major fucose-labeled glycoprotein in myelin of undernourished rats had a slightly higher apparent molecular weight than that in myelin from same age controls, corresponding to younger age. These results are similar to previous observation on hypothyroid rats (J.-M. Matthieu et al., Brain Res. 84: 443, 1975) and suggest that in undernutrition myelination is not only depressed but also delayed.