Differential trypsin effect upon (1-14C) acetate incorporation into choline and ethanolamine glycerophosphatides of rat brain and liver

Preincubation of rat brain and liver slices in a medium (5% glucose, 5% fructose, 1% albumin, 1% trypsin, 10 mM phosphate buffer pH 6.0) used to pretreat brain tissue for the separation of cell types was found to uncouple the incorporation of (1-¹⁴C) acetate into ethanolamine phosphoglycerides from that of the choline phosphoglycerides. Incorporation into ethanolamine phosphoglycerides was stimulated in both brain (330%) and liver (780%) slices, while the incorporation of (1-¹⁴C) acetate into choline phosphoglycerides was reduced for both brain (71%) and liver (63%) slices, compared to control values from nonpreincubated material. With (1-¹⁴C) linolenic acid as a precursor, no significant differences were found in incorporation into ethanolamine phosphoglycerides and choline phosphoglycerides.