Effects Of Preemptive Intrathecal Lornoxicam On Behavior And Expression Of C-Fos Protein In The Spinal Cord Of The Formalin Test Rats

OBJECTIVE: The objective of this study was to investigate an antinociceptive effect of preemptive intrathecal lornoxicam on behavior and expression of c-Fos protein in the spinal cord of the formalin test rats. METHODS: Forty-two healthy male adult SD rats (200-250g) were randomized into 7 groups. In the normal saline control group (group NS), 20μL of normal saline was injected intrathecally, followed by a subcutaneous administration of 100 μL of normal saline into the hind plantar 10 minutes later. In the formalin control group (group F), 20μL of normal saline was injected intrathecally, followed by an intra-plantar administration of 100μL of 5% formalin. In the intrathecal lornoxicam experiment groups (groups LorIT60-300), lornoxicam 60, 120, 180, 240, and 300 μg /20μL were administered intrathecally, respectively, followed by an intra-plantar administration of 100μL of 5% formalin. The graded pain behavior was observed and the nociceptive behavior index (NBI) was calculated every 5 minutes for one hour immediately after the formalin injection. At the 2-hour time point, all the rats were deeply anesthetized and were perfused intracardially; and then, the spinal cord was removed for analysis of c-Fos...