Nociceptor-selective peripheral nerve block induces delayed mechanical hypersensitivity and neurotoxicity in rats.

摘要: Background: Long-lasting, sensory-specific peripheral nerve blockade would advance perioperative analgesia. Perineural injection of a combination transient receptor potential vanilloid 1 channel agonists and lidocaine or its hydrophilic derivative, QX-314, produces prolonged sensory nociceptor-selective block in rodents. In this study, the authors tested efficacy these combinations after incisional surgery rats. Methods: The administered perisciatic (2%), QX-314 (0.2%) followed by dilute capsaicin (0.05%, 10 min later), vehicle rats duration motor to thermal mechanical stimuli assessed normal animals those hind paw. Other receiving injections were evaluated 7 weeks later behavior histology for neurotoxicity. Results: not only attenuated hypersensitivity 72 h incision but also resulted delayed onset several later, accompanied degeneration central terminals isolectin B4 (nonpeptidergic) calcitonin gene–related peptide–containing (peptidergic) afferents ipsilateral spinal cord. Dorsal root ganglia showed increased expression activating transcription factor-3 satellite cell activation. Conclusions: Combined administration local anesthetics with agonist induced near complete incision-induced days. However, same neurotoxicity naive Combination drugs concentrations is likely result neurotoxicity, safety other warrants further study.