Immunocytochemical analysis of rat vagus nerve by antibodies against glycogen phosphorylase isozymes.
Glycogen is an endogenous store of glucose equivalents for energy metabolism in many tissues. The brain contains a significant amount of glycogen the role of which as an energy reserve is currently under debate. Apparently little is known concerning a possible role of glycogen in peripheral nerves. We have demonstrated immunocytochemically the presence of glycogen phosphorylase (GP), a key enzyme in glycogen metabolism, in large and small axons of the rat vagus nerve, but not in Schwann cells. Furthermore, the isozyme-specific antibodies applied detected only the presence of the brain isoform BB of GP, but not the muscle isoform MM. This is in agreement with the occurrence of solely the BB isoform in the few brain and spinal cord neurons that contain GP. In contrast, astroglial cells in brain and spinal cord have previously been shown to contain both isoforms. Since GP isozymes are regulated differentially, the expression of isoform BB may provide hints to possible functions of glycogen in the vagus nerve.
Pfeiffer-Guglielmi
Brigitte
B
Interfakultäres Institut für Biochemie, Universität Tübingen, Hoppe-Seyler-Str 4, Tübingen, Germany.
Coles
Jonathan A
JA
Francke
Mike
M
Reichenbach
Andreas
A
Fleckenstein
Burkhard
B
Jung
Günther
G
Nicaise
Ghislain
G
Hamprecht
Bernd
B
D000818:Animals; D015153:Blotting, Western / Q000379:methods; D005260:Female; D025002:Glycogen Phosphorylase, Brain Form / Q000378:metabolism*; D024982:Glycogen Phosphorylase, Muscle Form / Q000378:metabolism*; D007150:Immunohistochemistry / Q000379:methods*; D008297:Male; D046529:Microscopy, Electron, Transmission / Q000379:methods; D009414:Nerve Growth Factors / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000378:metabolism; D014630:Vagus Nerve / Q000201:enzymology* / Q000648:ultrastructure
D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins; D025002:Glycogen Phosphorylase, Brain Form; D024982:Glycogen Phosphorylase, Muscle Form