Increased expression of tetrodotoxin-resistant sodium channels Nav1.8 and Nav1.9 within dorsal root ganglia in a rat model of bone cancer pain

Abstract In attempt to understand the underlying mechanisms of cancer-induced bone pain, we investigated the presence of two tetrodotoxin-resistant sodium channels, Nav1.8 (SNS/PN3) and Nav1.9 (SNS2/NaN), in dorsal root ganglia (DRG) neurons in an animal model of bone cancer pain. Thirty-six female Sprague-Dawley rats were randomized into three groups: Sham operation group (Sham), cancer-bearing animals killed after 7 days (C7) and cancer-bearing animals killed after 14 days group (C14). After establishment of bone cancer pain model, behavioral tests were carried out to determine the paw withdrawal threshold (PWT) of mechanical and thermal hyperalgesia, respectively. Real-time RT-PCR, Western bolt and Immunofluorescence were used to determine the mRNA and protein expression of Nav1.8 and Nav1.9 in ipsilateral lumbar 4-5 DRG. Compared to Sham group, PWT of mechanical and thermal hyperalgesia in C14 group displayed a significant decrease ( P P P P