5-羟色胺能机制在印度红蝎（Mesobuthus tamulus）毒液诱导的胃收缩中的作用。

Role of serotonergic mechanism in gastric contractions induced by Indian Red Scorpion (Mesobuthus tamulus) venom.

机构信息

Department of Physiology, Institute of Medical Sciences, Banaras Hindu University, Varanasi - 221005, India.

出版信息

Indian J Pharmacol. 2009 Dec;41(6):255-7. doi: 10.4103/0253-7613.59923.

DOI:10.4103/0253-7613.59923

PMID:20407555

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2846498/

Abstract

AIM

Gastric dysfunctions are commonly seen after scorpion envenomation, and the underlying mechanisms are not clear. Therefore, the present study was undertaken to investigate the effect of Indian red scorpion (Mesobuthus tamulus, MBT) venom on gastric fundus muscle contraction and the underlying mechanisms involved.

MATERIALS AND METHODS

In vitro isometric contraction was recorded from gastric fundus muscle strips on a chart recorder. The tissue was exposed to different concentrations of serotonin or crude MBT venom. The contractile responses to venom were expressed as the percentage of maximum contraction produced by serotonin at the beginning of each experiment. The contractile responses to 1.0 mug/ml of crude MBT venom were ascertained in the absence or presence of serotonin antagonist, methysergide.

RESULTS

Serotonin produced concentration-dependent fundus contractions (0.004-4.0 muM), and maximum contractile response was observed at 4.0 muM of serotonin. Hence, the contractile response obtained at 4.0 muM of serotonin was taken for normalization. The crude MBT venom (0.1-1.0 mug/ml) produced a concentration-dependent increase in fundus contractions (as % of maximum fundus contraction produced by serotonin at 4.0 muM). The maximum response was observed at 1.0 mug/ml of crude venom and a further increase in the concentration, up to 3.0 mug/ml, did not increase the response. In a separate series of experiments, pre-treatment with methysergide (1.0 muM) significantly attenuated the contractile response elicited by the venom (1.0 mug/ml) (P<0.05) and blocked the serotonin (4.0 muM) response.

CONCLUSION

The results suggest that the crude MBT venom produces gastric fundus contractions by partially involving serotonin.

摘要

目的

蝎毒中毒后常出现胃部功能障碍，但发病机制尚不清楚。因此，本研究旨在探讨印度红蝎（Mesobuthus tamulus，MBT）毒液对胃底肌收缩的影响及其潜在机制。

材料和方法

在图表记录器上记录胃底肌条的体外等长收缩。组织暴露于不同浓度的 5-羟色胺或粗 MBT 毒液。毒液的收缩反应表示为每个实验开始时 5-羟色胺产生的最大收缩的百分比。在没有或存在 5-羟色胺拮抗剂麦角乙脲的情况下，确定 1.0 µg/ml 粗 MBT 毒液的收缩反应。

结果

5-羟色胺产生浓度依赖性胃底收缩（0.004-4.0 µM），最大收缩反应发生在 4.0 µM 的 5-羟色胺。因此，将 4.0 µM 5-羟色胺时获得的收缩反应用于归一化。粗 MBT 毒液（0.1-1.0 µg/ml）产生浓度依赖性胃底收缩增加（作为 4.0 µM 5-羟色胺产生的最大胃底收缩的百分比）。最大反应发生在 1.0 µg/ml 的粗毒液，进一步增加浓度至 3.0 µg/ml 不会增加反应。在另一系列实验中，麦角乙脲（1.0 µM）预处理显著减弱了毒液（1.0 µg/ml）引起的收缩反应（P<0.05）并阻断了 5-羟色胺（4.0 µM）反应。