Ultrastructure of myelinated fibers of sciatic nerve in acute vincristine intoxication.
Numerous clinical reports documented that in some patients vincristine (VCR) may cause a risk for life (stridor) and painful symptoms of acute intoxication. The present study was undertaken to examine ultrastructural changes in the sciatic nerve of rabbits following acute vincristine intoxication. Our results show, that in a few hours, some axons of this nerve may undergo degeneration and atrophy. These changes were initially followed by the cleavage of adaxonal myelin sheets, that spontaneously formed concentric scrolls and tangled threads. Finally, myelin sheath collapsed around the atrophied axon. The results provide evidence that acute VCR intoxication primarily affects the axons. Myelin changes are caused by the loss of supportive role of atrophied axon for the myelin sheath. The effect of intoxicated Schwann cells on the myelin in acute VCR intoxication is not clear and requires further study.
Maéslińska
D
D
Laboratory of Developmental Neuropathology, Polish Academy of Sciences, Warszawa.
Muzylak
M
M
D000208:Acute Disease; D000367:Age Factors; D000818:Animals; D001284:Atrophy; D001369:Axons / Q000648:ultrastructure; D005260:Female; D008297:Male; D008854:Microscopy, Electron; D009186:Myelin Sheath / Q000648:ultrastructure; D009413:Nerve Fibers, Myelinated / Q000648:ultrastructure*; D009498:Neurotoxins / Q000633:toxicity*; D015388:Organelles / Q000648:ultrastructure; D010523:Peripheral Nervous System Diseases / Q000139:chemically induced* / Q000473:pathology; D011817:Rabbits; D012583:Schwann Cells / Q000648:ultrastructure; D012584:Sciatic Nerve / Q000648:ultrastructure*; D014750:Vincristine / Q000633:toxicity*
D009498:Neurotoxins; D014750:Vincristine