Defense Date

1985

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Biochemistry

First Advisor

George H. DeVries

Abstract

Purified Schwann cells were cultured from neonatal rat sciatic nerve using a modification of the method of Brockes (Brockes, J.P. et al, Brain Res. 165(1979) 105-118). Schwann cells and contaminating fibroblasts were unambiguously identified using fluorescent antibodies to 2'3' cyclic nucleotide 3'-phosphodiesterase and the thy 1.1 antigen respectively. The Schwann cells were quiescent unless challenged with mitogens, They proliferated rapidly in response to the soluable mitogen, cholera toxin, or to membrane fractions from rat CNS or PNS, prepared by the method of DeVries (DeVries, G.H., J Neurochem, 40 (1983) 1709-1717). Mitogenic activity was present in both axolemmal and myelin enriched fractions and promoted a 10-15 fold increase in the rate of 3H-thymidine uptake. The axolemmal mitogen was sensitive to heat (800C for 10 minutes), trypsin digestion (0.05% x 30 mins) or to treatment with endoglycosidase D, suggesting that it could be a glycoprotein. Fifty percent of the axolemmal mitogenic activity was solubilized in 1% octyl-glucoside. The solubilized material, however, was very unstable and further purification was not possible.

The myelin associated mitogenic activity was markedly different. It was resistant to freeze thaw cycles, trypsin digestion or endoglycosidase treatment and the activity was actually enhanced by heating at 100°C for two hours. It is proposed that the axolemmal activity is responsible for Schwann cell proliferation during development and that the myelin associated activity promotes Schwann cell proliferation during Wallerian degeneration.

Rights

© The Author

Is Part Of

VCU University Archives

Is Part Of

VCU Theses and Dissertations

Date of Submission

9-26-2016

Included in

Biochemistry Commons

Share

COinS