The relationship between antinociceptive effect of intrathecal tramadol and the a2-adrenoccptor effect of the spinal cord in rats
- VernacularTitle:大鼠鞘内注射曲马多的抗伤害性效应及与脊髓?_2受体效应的关系
- Author:
Kexuan LIU
;
Bingxue CHEN
;
Ziqing HEI
- Publication Type:Journal Article
- Keywords:
Tramadol;
Injections,spinal;
Receptors, adrenergic, alphaa2;
Pain measurement
- From:
Chinese Journal of Anesthesiology
1996;0(09):-
- CountryChina
- Language:Chinese
-
Abstract:
0.05), but pretreatment with yohimbine 10 ug significantly reduced the antinociceptive effect of tramadol ( 10ug) at 35 min and 40 min and the nociception score increased by 56% and 41 % respectively ( P 0.05). Scatchard analysis of the saturation isotherms showed that H-yohimbine was bound to a single binding site with a Kd value of 1.79 nM. The competition curve of tramadol was sigmoidal with a Ki value of 34.14 uM and an IC50 value of 68.25 uM. Tramadol was 19 000-fold less potent for binding to a2-adrenoceptor of the spinal cord as compared to H-yahimbine. Conclusion Intrathecal tramadol produces time-dependent antinociception. Tramadol has very low affinity with a2-adrenoceptor of the spinal cord. A part of its intrathecal antinociceptive effect was related to indirect a2-adrenoceptor effect of the spinal cord.
