Title page for ETD etd-06072011-152618


Type of Document Dissertation
Author Bustamante Diaz, Hedie A
Author's Email Address hedie@vt.edu
URN etd-06072011-152618
Title The role of potassium buffering and apoptosis of trigeminal satellite glial cells in the induction and maintenance of orofacial neuropathic pain in rats
Degree PhD
Department Veterinary Medical Sciences
Advisory Committee
Advisor Name Title
Klein, Bradley G. Committee Chair
Ehrich, Marion F. Committee Co-Chair
Jortner, Bernard S. Committee Member
Rossmeisl, John H. Jr. Committee Member
Keywords
  • neuropathic pain
  • Satellite glial cells
  • potassium
  • apoptosis
Date of Defense 2011-05-31
Availability unrestricted
Abstract
Satellite glial cells (SGC) are laminar cells that wrap completely around the sensory neuron and are responsible for buffering extracellular K+ after neuronal excitation. A decrease in the potassium buffering capacity of SGC has been associated with neuropathic pain (NP) behavior and apoptosis. This dissertation investigated the role of the potassium buffering capacity and apoptosis of trigeminal satellite glial cells (SGC) in the maintenance and development of orofacial NP in rats using in vivo and in vitro methodologies. In vivo endpoints were evaluated after performing chronic constriction injury (CCI) of the infraorbital nerve (IoN). NP signs and behavior were evaluated at 5, 10, 20 40 and 80 hours after injury. We evaluated the potassium buffering capacity of SGC by measuring the intracellular potassium concentration and protein levels and gene expression of the Kir4.1 and the SK3 potassium channels and gap junction protein connexin 43 (Cx43). We evaluated apoptosis endpoints including protein levels and gene expression of apoptotic related proteins bcl-2, caspase 9, caspase 3 and p53. Results indicate that NP signs developed as early as 5 hours after injury. After PNI, SGC responded by increasing their intracellular potassium concentration and by increasing protein levels of Kir4.1, SK3 and Cx43. Nonetheless, this increase in protein levels was not accompanied by an increase in gene expression. Apoptosis results revealed that SGC decreased protein levels and gene expression of anti-apoptotic protein Bcl-2. Using in vitro methodologies, we developed primary trigeminal SGC cultures and evaluated how a decrease in the intracellular potassium concentration modulates apoptosis induced by the mitochondrial and death receptor pathways. SGC depleted of potassium after hypoosmotic shock showed a significant increase in early apoptosis after incubation with mitochondrial pathway apoptotic inducer staurosporine when compared to SGC with normal intracellular concentration. This research has revealed that SGC respond early to PNI by increasing their potassium buffering capacity. We also determined that the mitochondrial apoptotic pathway might be involved in the trigeminal SGC response to PNI. From our in vitro experiments we have revealed that potassium is an important modulator of apoptosis induced by the mitochondrial pathway in cultured trigeminal SGC.
Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  BustamanteDiaz_HA_D_2011.pdf 10.67 Mb 00:49:25 00:25:24 00:22:14 00:11:07 00:00:56

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.