ABSTRACT
BACKGROUND: Recent research has shown that reactive oxygen species (ROS) play a significant role in the development and persistence of neuropathic pain through central sensitization via N-methyl-D-aspartate (NMDA) receptor activation. In the present study, we examined whether the intraperitoneal administration of vitamins C and E alone or together could alleviate mechanical allodynia in a chronic post-ischemia pain (CPIP) rat model. METHODS: Vitamins C and E were administered intraperitoneally to 48 male Sprague Dawley rats once per day for 3 days before hindpaw ischemia-reperfusion (I/R) injury was induced. On the third day, the CPIP rat model was produced by inducing ischemia in the left hindpaw by applying an O-ring for 3 h, followed by reperfusion. Three days after reperfusion, hindpaw mechanical allodynia was assessed by measuring the withdrawal response to von Frey filament stimulation. The rats were sacrificed immediately after behavioral testing to determine the phosphorylated NMDA receptor subunit 1 (pNR1) and extracellular-signal-regulated kinases (pERK) levels in the spinal cord. RESULTS: When the antioxidant vitamins C and E were administered intraperitoneally to CPIP rats, I/R injury-induced mechanical allodynia was attenuated, and pNR1 and pERK levels were decreased in the rat spinal cord. Additionally, the co-administration of both vitamins had an increased antiallodynic effect. CONCLUSIONS: The reduced phosphorylated NR1 and ERK levels indicate that vitamins C and E inhibit the modulation of spinal cord neuropathic pain processing. Co-administration of vitamins C and E had a greater antiallodynic effect.
Subject(s)
Animals , Humans , Male , Rats , Antioxidants , Ascorbic Acid , Central Nervous System Sensitization , Complex Regional Pain Syndromes , Hyperalgesia , Inositol Phosphates , Ischemia , Mitogen-Activated Protein Kinases , Models, Animal , N-Methylaspartate , Neuralgia , Phosphotransferases , Prostaglandins E , Rats, Sprague-Dawley , Reactive Oxygen Species , Receptors, N-Methyl-D-Aspartate , Reperfusion , Reperfusion Injury , Spinal Cord , Vitamin E , VitaminsABSTRACT
BACKGROUND: Although post operative pain has been reduced significantly since the advent of laparoscopic surgery, many patients still complain of moderate abdominal and shoulder pain after surgery. METHOD: Patients scheduled for elective laparoscopic cholecystectomy were assigned to three groups by simple randomization(12 patients per group). Group I patients(control) had no specific treatment, group II patients had 10 ml of normal saline instillation, and group III patients had 10 ml of 0.5% bupivacaine instillation. Instillation was made directly into the gallbladder bed and right subdiaphragmatic space under direct vision by the surgeon at the end of the procedure and before evacuating the pneumoperitoneum. RESULT: Compared to that of the group I, VAS of group II and III did not show any statistically significant difference. Compared to the group I, group II & III showed no significant difference in numbers of requests of Tiaprofenic acid during the 36hours after the surgery. CONCLUSION: Topical instillation of 0.5% bupivacaine 10 ml to the gallbladder bed and right subdiaphragmatic space after laparoscopic cholecystectomy is not effective for the post operative pain control.