Properties of Bovine Oligodendroglia Isolated by a New Procedure Using Physiologic Conditions

Abstract
A new class of procedures, previously shown to permit the isolation of pure oligodendroglia from whole rat cerebrum, has been applied with equal or greater success for the bulk isolation of this cell type from bovine white matter. Thus, the generality of this approach has been demonstrated. The bovine preparations have a purity of >90% intact, phase-bright oligodendroglia and are obtained in a yield of 8 × 106 cells per gram of white matter. Within 1 day it is possible to obtain a preparation containing 60 mg of protein from a single cell type. These cells show a higher degree of ultrastructural preservation of all cytoplasmic constituents than previously obtained. The values for protein (33 pg/cell), DNA (5.4 pg/cell), and lipid (5–6 pg/cell) are very similar to those obtained with an earlier procedure. The cell lipids are rich in galactolipid, which comprises 20% of the total. The activity of the “myelin-specific” enzyme, 2′,3′-cyclic nucleotide 3′-phosphohydrolase (EC 3.1.4.37), is 4.7 μmol/min/mg protein, similar to that obtained previously for isolated oligodendroglia and about 25–40% of that found in myelin. The activity of 5′-nucleotidase (EC 3.1.3.5) in the cells is about 10% of that in myelin or white matter.