Huwentoxin-Ⅰ: Antinociceptive Effects and Its Comparison with ω-Conotoxin-MVIIA on Acute Visceral Pain in Rats
- VernacularTitle:虎纹蜘蛛毒素-Ⅰ对大鼠急性内脏疼痛的抑制性效应及与ω-芋螺毒素的比较研究
- Author:
Jiaqin CHEN
;
Weihua CHEN
;
Meichun DENG
;
Guan LI
;
Yuan KANG
;
Songping LIANG
- Publication Type:Journal Article
- Keywords:
huwentoxin-Ⅰ (HWTX-Ⅰ );
N-type voltage-sensitive calcium channels;
visceral pain;
antinociception;
rat model;
ω-conotoxin-MVIIA
- From:
Chinese Journal of Biochemistry and Molecular Biology
2005;21(1):24-29
- CountryChina
- Language:Chinese
-
Abstract:
The antinociceptive effect of epidural administration of huwentoxin-I was elucidated in a tonic visceral pain rat model produced by acute colon inflammation. The nociceptive behaviors were induced by perendoscopically injecting dilute formalin (50 μl) into the depth of the colonic wall in rats. Both ω-conotoxinMVIIA and morphine hydrochloride were given epidurally as positive control while saline as negative control.Similar to ω-conotoxin-MVIIA and hydrochloride morphine, the epidural administration of HWTX-Ⅰ significantly reduced the nociceptive responses in a dose-dependent manner in tonic visceral pain rat model ( P ＜ 0.05). The suppression effects of both huwentoxin- Ⅰ and ω-conotoxin-MVIIA at 20 μg/kg were kept steady compared with the saline group and reached their maximum effects at the doses of 50 ～ 75 μg/kg within 1 hour when the nociception had been observed. It was also found that at the same doses, huwentoxin- Ⅰ was less effective in antinociception than ω-conotoxin-MVIIA. However, ω-conotoxin-MVIIA, but not huwentoxinⅠ , caused an obvious motor dysfunction at these doses. The action of morphine hydrochloride was initiated faster, but lasted for a shorter time than that of huwentoxin- Ⅰ and ω-conotoxin-MVIIA. Thus, huwentoxinⅠ , a potent blocker of neuronal N-type voltage-sensitive calcium channels, induced a remarkable dosedependent restrain effect similar to ω-conotoxin-MVIIA and morphine on the tonic visceral pain produced by colonic wall injection of formalin in conscious rats.
