title: Effect of ethyl pyruvate on Paclitaxel-induced neuropathic pain in rats.
abstract: BACKGROUND
  Although paclitaxel is a widely used chemotherapeutic agent for the treatment of solid cancers, side effects such as neuropathic pain lead to poor compliance and discontinuation of the therapy. Ethyl pyruvate (EP) is known to have analgesic effects in several pain models and may inhibit apoptosis. The present study was designed to investigate the analgesic effects of EP on mechanical allodynia and apoptosis in dorsal root ganglion (DRG) cells after paclitaxel administration.
  
  
  METHODS
  Rats were randomly divided into 3 groups: 1) a control group, which received only vehicle; 2) a paclitaxel group, which received paclitaxel; and 3) an EP group, which received EP after paclitaxel administration. Mechanical allodynia was tested before and at 7 and 14 days after final paclitaxel administration. Fourteen days after paclitaxel treatment, DRG apoptosis was determined by activated caspase-3 immunoreactivity (IR).
  
  
  RESULTS
  Post-treatment with EP did not significantly affect paclitaxel-induced allodynia, although it tended to slightly reduce sensitivities to mechanical stimuli after paclitaxel administration. After paclitaxel administration, an increase in caspase-3 IR in DRG cells was observed, which was co-localized with NF200-positive myelinated neurons. Post-treatment with EP decreased the paclitaxel-induced caspase-3 IR. Paclitaxel administration or post-treatment with EP did not alter the glial fibrillary acidic protein IRs in DRG cells.
  
  
  CONCLUSIONS
  Inhibition of apoptosis in DRG neurons by EP may not be critical in paclitaxel-induced mechanical allodynia.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
authors.forename: Seong Soo
authors.initials: SS
authors.lastname: Choi
authors.forename: Won Uk
authors.initials: WU
authors.lastname: Koh
authors.forename: Jae Sik
authors.initials: JS
authors.lastname: Nam
authors.forename: Jin Woo
authors.initials: JW
authors.lastname: Shin
authors.forename: Jeong Gill
authors.initials: JG
authors.lastname: Leem
authors.forename: Jeong Hun
authors.initials: JH
authors.lastname: Suh
keywords: allodynia; apoptosis; dorsal root ganglion; ethyl pyruvate; paclitaxel