A Proteomic Approach for Quantitative Analysis of Calcitonin Gene-related Peptides in the Cerebrospinal Fluid Obtained from a Rat Model of Chronic Neuropathic Pain / 대한통증학회지

ABSTRACT

BACKGROUND: This study was conducted to quantitatively analyze proteins associated with the calcitonin gene-related peptide (CGRP) in cerebrospinal fluid (CSF) that was obtained from a rat model of chronic neuropathic pain following administration of intrathecal CGRP(8-37). METHODS: Male Sprague-Dawley rats (100-150 g, 5-6 wks) were divided into two groups, sham controls and neuropathic pain models. At the time of operation for neuropathic pain model, an intrathecal catheter was threaded through the intrathecal space. At 1 or 2 wks after the operation (maximum pain state), a test dose of 1, 5, 10, or 50 nM of CGRP(8-37) was injected into the intrathecal catheter and the CSF was then aspirated. Conventional proteomics to evaluate the CSF were then performed using high resolution 2-D, gel electrophoresis followed by computational image analysis and protein identification by mass spectrometry. RESULTS: Treatment with CGRP(8-37) effectively alleviated mechanical allodynia in a dose dependent manner. The most effective response was obtained when a dose of 50 nM was administered, but significant differences were obtained following administration of only 5 nM CGRP(8-37). Furthermore, the results of the proteomic analysis were consistent with the experimental results. Specially we detected 30 differentially expressed spots in 7 images when 2-D gel electrophoresis was conducted. The intensity of 6 of these spots (spot number 20 and 26-30) was found decrease the CGRP(8-37) dose increased; therefore, these spots were evaluated by mass spectrometry. This analysis identified 2 different proteins, CGRP (spot numbers 26-30) and neurotensin-related peptide (spot number 20). CONCLUSIONS: The results of this study suggest that CGRP plays a role in chronic central neuropathic pain and is a major target of chronic neuropathic pain management.