Altered expression and function of sodium channels in large DRG neurons and myelinated A-fibers in early diabetic neuropathy in the rat.
Biochem Biophys Res Commun
; 339(2): 652-60, 2006 Jan 13.
Article
in En
| MEDLINE
| ID: mdl-16310161
ABSTRACT
Differential alterations of sodium channels in small nociceptive C-fiber DRG neurons have been implicated in diabetic neuropathy. In this study, we investigated sodium currents and the expression of sodium channels in large A-fiber DRG neurons in diabetic rats. Compared with controls, large neurons from diabetic rats showed significant increases in both total and TTX-S sodium currents and approximately -15mV shifts in their voltage-dependent activation kinetics. TTX-R Na(v)1.9 sodium current was also significantly increased, whereas no alteration of TTX-R Na(v)1.8 current was observed in neurons from diabetic rats. Sodium current induced by fast- or slow-voltage ramps increased markedly in the diabetic neurons as well. Immunofluorescence studies showed significant increases in the levels and number of large DRG neurons from diabetic rats expressing Na(v)1.2, Na(v)1.3, Na(v)1.7, and Na(v)1.9 whereas Na(v)1.8 decreased. We also observed a decrease in the number of nodes of Ranvier expressing Na(v)1.8 and in staining intensity of Na(v)1.6 and Na(v)1.8 at nodes. Our results suggest that alterations of sodium channels occur in large DRG neurons and A-fibers, and may play an important role in diabetic sensory neuropathy.
Search on Google
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Sodium Channels
/
Diabetic Neuropathies
/
Ganglia, Spinal
/
Nerve Fibers, Myelinated
/
Neurons
Type of study:
Prognostic_studies
Limits:
Animals
Language:
En
Journal:
Biochem Biophys Res Commun
Year:
2006
Type:
Article
Affiliation country:
United States