Effects of different doses of gabapentin on streptozotocin-induced diabetic neuropathic pain / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effects of different doses of gabapentin on streptozotocin (STZ)-induced diabetic neuropathic pain in rats.Methods Male SD rats aged 6 weeks weighing 180-200 g were used in this study. Diabetes ntellitus ( DM) was induced by intraperitoneal STZ 60 mg/kg and confirmed one week later by blood glucose =16.7 mmol/L before breakfast. The DM rats were randomly divided into 4 groups ( n = 6 each) : gabapentin groups received intraperitoneal gabapentin 30, 60 and 120 mg/kg twice a day (at 9:00 am and 3:00 pm) for 3 weeks respectively and control group received intraperitoneal normal saline 0.6 ml instead of gabapentin. The paw withdrawal threshold to von Frey filament stimulation was measured before and at 30, 60, 120, 180, 240 min after first gabapentin injection and once a week for 3 weeks. Results After gabapentin 60 and 120 mg/kg, the paw withdrawal threshold to mechanical stimuli was significantly increased and lasted for about 4 h. The analgesic effect peaked at 60 min after IP gabapentin injection. Normal saline and gabapentin 30 mg/kg had no significant analgesic effect. The degree of analgesia was significantly decreased at day 14 and 21 of treatment with gabapentin 60 and 120 mg/kg as compared with that at 60 min after gabapentin injection. Conclusion The hyperalgesia and allodynia in rats with diabetes mellitus can be effectively reversed by gabapentin 60 and 120 mg/kg,while long-term use of gabapentin can induce drug tolerance.