Incorporation of [14C]Glucose into Lipids of Bovine Oligodendroglia

Abstract

Oligodendrocytes were isolated from the white matter of ox brains. Light microscopy revealed that the cells were .gtoreq. 90% phase-bright with a mean diameter of 7.6 .mu.m. Transmission EM was employed to identify the classic morphology associated with mature oligodendrocytes. Homogenates of the isolated cells showed negligible activity of neuronal and astrocytic cell markers. Using a suspension culture method cells were incubated with [14C]glucose. This simple precursor labeled the 5 complex lipids choline glycerophospholipid, ethanolamine glycerophospholipid, inositol glycerophospholipid + serine glycerophospholipid, and the 2 cerebroside species. The incorporation of label was shown to be dependent on glucose concentration, protein concentration and the length of incubation. In addition the glucose uptake blocker phloretin (1 mM) reduced the degree of labeling by up to 97%, and the metabolic poisons KCN (1 mM) and iodoacetate (0.5 mM) had varying deleterious effects on the amounts of labeling of the 5 lipids measured.