THE FORMATION OF PHOSPHOLIPIDS FROM C14-LABELLED PRECURSORS IN SLICES FROM IMMATURE RAT BRAIN

Abstract

The relative incorporation of several C14-labelled compounds into the phospholipid and free cholesterol of developing rat brain slices at various ages from 1 to 19 days was examined. Experiments have shown that labelling of saturated fatty acids of phospholipids and cholesterol from acetate-1-C14and propanoate-1-C14was much more in 1- to 9-day animals than in older animals while the labelling from non-fatty acid precursors such as ethanolamine-1,2-C14and choline-Me-C14was not greatly affected by the aging processes. Palmitic acid was the major acid labelled by acetate, but both stearic and myristic acids received appreciable activity.The results tend to indicate that the saturated fatty acids of rat brain phospholipids are formed rapidly at a very early stage in brain development. The activity of this synthetic system then appears to decrease to the low level apparent in the adult rat. The glycerol–phosphate-base moieties of the phospholipids, on the other hand, appear to retain their relatively high replacement activity at all ages.