PROTEIN-BOUND PHOSPHORUS COMPOUNDS IN THE PROXIMAL STUMP OF PERIPHERAL NERVE AFTER NERVE SECTION OR AFTER NERVE CRUSH

Abstract

The concentration of acid-soluble P, lipid P, protein-bound P, total nucleic acid, DNA (desoxypentosenucleic acid), PNA (pentosenucleic acid), PP (“phosphoprotein”), and “inositide P” was determined in the proximal stump of the sciatic nerve of the cat at 16, 32, and 96 days after nerve section and at 2, 4, 8, 16, 32, and 96 days after nerve crush. There was an increase in the concentration of acid-soluble P at 16 days after nerve section and a decrease in the concentration of PP at 96 days after either nerve section or nerve crush. The lipid P decreased slightly at 96 days after nerve section and the “inositide P” increased somewhat at 96 days after nerve crush, but both of these fractions remained normal at the other time intervals. The greatest changes, however, were observed in the concentration of the nucleic acids. The concentration of total nucleic acid, DNA, and PNA increased after nerve section, the DNA concentration reaching a maximum at 96 days and the PNA at 16 days. The increase in the concentration of nucleic acid after nerve crush was smaller than that observed after nerve section, the greatest difference being noted at 96 days. These increases in the concentration of nucleic acids, which are not so marked as those in the distal stump, suggest that some cellular proliferation occurs, not only in the distal stump, but also in the proximal stump following either nerve section or nerve crush.