The effect of long-term low protein intake on lipids of rat brain during adulthood.

The effect of experimental protein malnutrition on growth, brain tissue weight and lipid composition was studied in male Wistar rats fed isoenergetic diets containing 22% (C-22) or 6% protein (PD-6) from 60 days until 240 days of age. At 240 days of age the mean weight of PD-6 rats was 63% that of control rats. Protein malnutrition initiated at 60 days of age affected lipid composition by 240 days of age. The total content of phospholipids and the phosphatidylethanolamine, phosphatidylcholine, phosphatidylserine and phosphatidylinositol fractions were not significantly changed in rats ingesting the PD-6 diet, but phosphatidylglycerol and sphingophospholipid fractions were significantly decreased in the brains of PD-6 rats. Such a diet did not cause a statistically significant decrease of the total amount of monogalactosyl glycolipid or of most investigated fractions (cerebrosides with hydroxy fatty acids, sulfoglycolipids and monogalactosyldiacylglycerols), except for cerebrosides with nonhydroxy fatty acids. Long-term, low protein intake did not cause a significant decrease in the total ganglioside content, but had an effect on the composition of single investigated ganglioside fractions (GM1, GD1a, GD1b and GT1a).