Differential expression of alpha-adrenoceptor subtypes in rat dorsal root ganglion after chronic constriction injury
- 171 Downloads
mRNAs of alpha-adrenoceptor (α-AR) subtypes are found in neurons in dorsal root ganglion (DRG) and change after peripheral nerve injury. In this study, the distribution of α-AR subtype proteins was studied in L5 DRG of normal rats and rats with chronic constriction injury of sciatic nerve (CCI). Using immunofluorescence technique, it was found that α1A-, α1B-, and α2A-AR proteins were expressed in large, medium, and small size neurons in normal DRG, and significantly increased in all size neurons 14 days after CCI. α1D- and α2C-AR was also expressed in all size neurons in normal DRG. However, α1D-AR was significantly increased and α2C-AR was decreased in small size neurons 14 days post CCI. α2B-AR neurons were not detectable in normal and CCI DRG. Co-expression of α1A- and α2A-AR in the same neuron was observed in normal DRG and increased post CCI. Collectively, these results indicated that there is distinct distribution of α-AR subtypes in DRG neurons, and the distribution and levels of expression of α-AR subtypes change differently after CCI. The up-regulation of α-AR subtypes in DRG neurons may play an important role in the process of generating and transmitting neuropathic pain.
Key wordsalpha-adrenoceptor chronic constriction injury dorsal root ganglion neuropathic pain noradrenaline
Unable to display preview. Download preview PDF.
- 27.Eisenach JC, Zhang Y, Duflo F. alpha2-adrenoceptors inhibit the intracellular Ca2+ response to electrical stimulation in normal and injured sensory neurons, with increased inhibition of calcitonin gene-related peptide expressing neurons after injury. Neuroscience, 2005, 131(1): 189–197PubMedCrossRefGoogle Scholar
- 32.Tamagaki S, Suzuki T, Hagihira S, et al. Systemic daily morphine enhances the analgesic effect of intrathecal dexmedetomidine via up-regulation of alpha 2 adrenergic receptor subtypes A, B, and C in dorsal root ganglion and dorsal Horn. J Pharm Pharmacol, 2010, 62(12): 1760–1767PubMedCrossRefGoogle Scholar