Ganglioside synthesis and transport in regenerating sensory neurons of the rat sciatic nerve.
The sciatic nerves of rats were crushed with fine forceps and allowed to survive for 3 or 7 days, at which time the 5th lumbar dorsal root ganglion was injected with [3H]glucosamine. Animals were killed 18 h later and the nerves proximal and distal to the crush site were cut into 3 mm segments. Gangliosides were purified from these segments, and radioactivity was separately measured in gangliosides, neutral glycolipids and glycoproteins. For all 3 fractions, radioactivity was distributed similarly between the crush site and point of maximum axonal elongation. A second smaller peak of ganglioside radioactivity was seen to span a few segments immediately distal to the point of maximum axonal elongation. We propose two possible explanations for this: (1) it represents ganglioside synthesis by Schwann cells (from blood-borne [3H]glucosamine) as part of the mitogenic response of these cells to the reappearance of axons; or (2) recently synthesized, transported gangliosides are released from the growth cone and taken up by adjacent mitogenic Schwann cells.
Yates
A J
AJ
Department of Pathology, College of Medicine, Ohio State University, Columbus 43210.
Warner
J K
JK
Stock
S M
SM
McQuarrie
I G
IG
D000818:Animals; D001370:Axonal Transport; D005732:Gangliosides / Q000096:biosynthesis* / Q000378:metabolism; D006023:Glycoproteins / Q000378:metabolism; D008297:Male; D009416:Nerve Regeneration; D009475:Neurons, Afferent / Q000378:metabolism / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012584:Sciatic Nerve / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D013997:Time Factors
D005732:Gangliosides; D006023:Glycoproteins