A useful correlation between blood and brain N-acetylneuraminic acid contents

A study was conducted to determine if serum N-acetylneuraminic acid (NeuAc) levels correlate with brain NeuAc levels. Sprague-Dawley rats were given either a diet containing 100 g casein/kg or one with 200 g casein/kg throughout pregnancy and lactation. At 12, 16 and 21 days' postpartum, litters of pups from each of the groups were killed. Their serum was assayed for NeuAc and their brains for total ganglioside and glycoprotein NeuAc. It was found that brain wet weight, ganglioside and glycoprotein NeuAc contents all correlate with serum NeuAc levels. It is suggested that serum NeuAc levels might represent a new method of measuring functional development of the brain.