Comparative study on analgesic effect of tetrodotoxin in four acute pain models
10.12206/j.issn.1006-0111.202101009
- VernacularTitle:河豚毒素对4种急性疼痛模型的镇痛效应比较研究
- Author:
Xuejun CHEN
1
;
Ruihua ZHANG
1
;
Tong SHI
1
;
Chen WANG
1
;
Jianfu XU
1
;
Liqin LI
1
Author Information
1. State Key Laboratory of NBC Protection for Civilian, Beijing 102205, China.
- Keywords:
tetrodotoxin;
morphine hydrochloride;
analgesic effect;
acute pain models
- From:
Journal of Pharmaceutical Practice
2022;40(1):70-75
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the analgesic effect of tetrodotoxin (TTX) in four types of acute pain models and provide experimental support for its rational application. Methods Mice or rats were intramuscularly pretreated with morphine (1 mg/kg) or TTX (0, 0.5, 1, 2, 4 and 8 μg/kg) 40 min before acetic acid writhing test, formalin stimulation test, hot plate test or tail flick test. Pain response or pain threshold were recorded, and inhibition rate was calculated during the tests. The arachidonic acid of serum was determined by Elisa. Results Significant analgesic effects were observed with morphine in all four acute pain models. TTX dose-dependently reduced the number of writhing induced by acetic acid and inhibited the pain response induced by formalin during phase I and phase II, with the highest inhibition rate of more than 80.00% in two pain models. TTX showed analgesic effect in tail flick test and hot plate test, with the highest inhibition rate of 25.00% and 19.79%, respectively. Both acetic acid and formalin increased arachidonic acid in animal serum, but TTX had no significant inhibitory effect on the releasing of arachidonic acid. Conclusion TTX showed significant analgesic effect in the chemical stimulation pain models induced by acetic acid and formalin, but limited analgesic effect was observed on the physical stimulation pain model induced by heat (hot plate and hot water). TTX may produce analgesic effect by blocking the inflammatory mediators mediating pain response.
