Inhibition of reactive gliosis in vivo by exogenous axolemma and myelin fractions.
Exogenous myelin- or axolemma-enriched fractions were assessed for the ability to inhibit biochemical and morphological expressions of reactive gliosis in rat optic nerve. Elvax pellets containing exogenous myelin, axolemma, whole-brain homogenate, liver, or red cell extracts or no homogenate were inserted into a dural slit in distal regions of crushed optic nerve. Biochemical and morphological expressions of reactive gliosis were assessed at 7 or 14 days postoperatively. Post-traumatic elevations in lactic dehydrogenase activity normally seen at 7 days postoperatively were prevented by placement of Elvax pellets containing myelin or axolemmal fractions into the optic nerve. Morphological analyses indicated an inhibition of post-traumatic elevations in glial cell numbers, surface area, and nuclear size at the 14-day time point. Exposure of the axolemmal fraction to heat or trypsin inactivated its ability to modulate reactive gliotic changes. Myelin fractions were trypsin-sensitive, but not heat-sensitive. In contrast, Elvax pellets containing whole-brain tissue homogenates or liver and red cell membranes had no significant effects on post-traumatic glial changes relative to preparations in which homogenate-free pellets were used.
Politis
M J
MJ
Department of Anatomy, School of Medicine, University of Saskatchewan, Saskatoon, Canada.
D000818:Animals; D001369:Axons / Q000502:physiology*; D001921:Brain / Q000503:physiopathology*; D005260:Female; D005911:Gliosis / Q000201:enzymology / Q000503:physiopathology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D009186:Myelin Sheath / Q000502:physiology*; D009441:Neurilemma / Q000502:physiology*; D009900:Optic Nerve / Q000201:enzymology / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains
D007770:L-Lactate Dehydrogenase