Correlation of mitochondrial swelling after capsaicin treatment and substance P and somatostatin immunoreactivity in small neurons of dorsal root ganglion in the rat.
Capsaicin injections into adult rats produced swelling of mitochondria in a population of small neurons of the dorsal root ganglia. Large neurons did not show the mitochondrial change. The mitochondrial swelling was confirmed to be a specific change produced by capsaicin treatment by the examination of different fixation conditions in both control and capsaicin-treated materials. Whether or not these mitochondrial changes occur in a subpopulation of small neurons which contain particular neurotransmitters was examined. The swelling of mitochondria was found in most substance P- or somatostatin-immunoreactive neurons and also in some non-immunoreactive small neurons. The present results indicate that the swelling of mitochondria is a specific change which may correlate with long-lasting desensitization of nociceptive neurons in the dorsal root ganglion after capsaicin treatment.
Chiba
T
T
Masuko
S
S
Kawano
H
H
D000818:Animals; D002211:Capsaicin / Q000008:administration & dosage*; D005727:Ganglia, Spinal / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D008933:Mitochondrial Swelling / Q000187:drug effects*; D009475:Neurons, Afferent / Q000145:classification* / Q000187:drug effects / Q000648:ultrastructure; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000378:metabolism*; D013194:Staining and Labeling; D013373:Substance P / Q000378:metabolism*; D013997:Time Factors
D013373:Substance P; D013004:Somatostatin; D002211:Capsaicin