二硫苏糖醇对离体兔肠系膜动脉的影响。

Effects of dithiothreitol on the isolated rabbit mesenteric artery.

作者信息

Horst M A, Robinson C P

出版信息

Agents Actions. 1982 Oct;12(4):443-9. doi: 10.1007/BF01965924.

DOI:10.1007/BF01965924

Abstract

Rabbit mesenteric artery strips exposed to 10(-3) M dithiothreitol (DTT) were contracted with a series of concentrations of histamine and 2-pyridylethylamine (PEA). DTT exposure increased the sensitivity to histamine 100-fold but increased the sensitivity to PEA only 4-fold. DTT did not reduce dimaprit-induced relaxations, but reduced histamine-induced relaxations. Following a high concentration of histamine (10(-3) M), DTT itself produced a sustained, slowly developing contraction (29 +/- 6.8% of the maximal contraction) relaxed by 7 X 10(-6) M mepyramine but not by 10(-6) M phentolamine. Metiamide (3 x 10(-5) M) potentiated DTT-induced contractions (29 +/- 6.8 before, 57 +/- 7.5% after metiamide, as a percent of maximal contraction). Changing the bathing fluid and repeating DTT exposure slowly relaxed previously contracted strips. DTT did not prevent the increase in sensitivity of relaxant histamine receptors on exposure to cold. We conclude that DTT, in addition to potentiating histamine H1-receptor responses, releases histamine presumably from non-mast cell pools when they are loaded with a high concentration of exogenous histamine.

摘要

将兔肠系膜动脉条暴露于10⁻³ M二硫苏糖醇（DTT）后，用一系列浓度的组胺和2-吡啶乙胺（PEA）进行收缩实验。暴露于DTT后，对组胺的敏感性增加了100倍，但对PEA的敏感性仅增加了4倍。DTT并未降低二甲双胍诱导的舒张，但降低了组胺诱导的舒张。在高浓度组胺（10⁻³ M）作用后，DTT本身产生了持续的、缓慢发展的收缩（最大收缩的29±6.8%），可被7×10⁻⁶ M美吡拉敏松弛，但不能被10⁻⁶ M酚妥拉明松弛。甲硫米特（3×10⁻⁵ M）增强了DTT诱导的收缩（甲硫米特前为29±6.8%，甲硫米特后为57±7.5%，以最大收缩的百分比表示）。更换浴液并重复DTT暴露可使先前收缩的动脉条缓慢舒张。DTT并不能阻止在暴露于寒冷时组胺舒张受体敏感性的增加。我们得出结论，DTT除了增强组胺H1受体反应外，当非肥大细胞池装载高浓度外源性组胺时，可能会释放组胺。