The effect of systemic application of NGF and anti NGF on experimential neuropathic pain model

2. ABSTRACTTHE EFFECT OF SYSTEMIC APPLICATION OF NGF AND ANTI-NGF ONEXPERIMENTAL NEUROPATHIC PAIN MODELThe mechanisms of neuropathic pain due to damage and/or dysfunction of thepart of nervous system are complicated. Nerve growth factor (NGF) is present in thesecomplex processes. Although there have been numerous experimental and clinicalinvestigations for understanding of the pathophysiology and lots of treatment modalitieshave been implicated for neuropathic pain management so far, pain could not beobviated yet. In this study, the effect of NGF and Anti-Nerve Growth Factor (anti-NGF)in experimental neuropathic pain model was aimed.Upon an approval of Local Ethic Committee obtained, 24 male Wistar-albinorats were taken into study and divided into 4 groups. All groups referred as controlgroup, saline group, NGF group, and anti-NGF group. Mechanical and thermal (heat,cold) pain thresholds were measured and recorded for each animal in the first day of theexperiment. In the same day, chronic constriction injury (CCI) was introduced to leftsciatic nerve for each animal except control groups. In the following days, mechano-thermal pain thresholds were measured for every day for each animal. It has been notedthat neuropathic pain was existed in 21st day of experiment in all CCI applied rats.Following neuropathic pain was obtained nothing was administered to control groupduring 28 days. For saline group; saline was administered s.c. whereas for NGF group, adose of 35 nanogram/gram NGF was administered s.c., for anti-NGF group, a dose of 9nanogram/gram anti-NGF was administered s.c. Mechano-thermal pain thresholds weremeasured for each animal during followed 28 days.It was determined that NGF increased mechanical hyperalgesia, heathyperalgesia, cold hyperalgesia between 22-32 days, 22-31 days, 22-28 days,respectively. However, it was noted that anti-NGF reduced mechanical hyperalgesia,heat hyperalgesia, cold hyperalgesia between 22-29 days, 22-28 days, 22-27 days,respectively.In conclusion; systemic applied NGF increased neuropathic pain, whereas anti-NGF diminished of this kind of pain.Key Words: NGF, anti-NGF, hyperalgesia, neuropathic pain.