Development of Na+-K+-ATPase in neonatal rat brain synaptosomes after perinatal protein malnutrition.

Four protein dietary groups of rats were used in this study, namely: 27% casein diet fed throughout gestation and lactation (group C-C); 27% gestation, 10% lactation (group C-D); 10% gestation, 27% lactation (group D-C); 10% throughout gestation and lactation (group D-D). Mean body weight of group D-D at warning was 19 g compared with 59 g for group C-C. The specific activity of Na+-K+-ATPase in isolated synaptosomes from cerebral and cerebellar tissues increases throughout the lactation period. At 1 and 7 days of age no differences in Na+-K+-ATPase activity are noted in the brain regions of Groups C-C and D-D. At 14 and 21 days, however, the specific Na+-K+-ATPase activity was significantly reduced in isolated synaptosomes from both brain regions of the protein-deprived group. ATPase activity in cerebellar synaptosomes from dietary exchange groups (C-D and D-C) developed to the same extent as that of the control group (C-C) after 21 days of lactation. ATPase activity in the cerebral synaptosomes of the dietary exchange group (C-D) did not develop to the same extent as that in the control group (C-C) and the other dietary exchange group (D-C).